Class 11 Physics Important Questions On Newsongoogle By Bilal Articles
Empower your Class 11 Physics studies with vital resources on Newsongoogle by Bilal Articles! Explore important questions, comprehensive chapter notes, past papers, and insightful guess papers. Elevate your understanding of Physics with expertly curated content designed for Class 11 students. Accelerate your academic success in Physics with our specialized educational materials.
Physical World Class 11 Important Extra Questions Physics Chapter 1
- Name that branch of science that deals with the study of Earth.
- Name that branch of science that deals with the study of stars.
- Name the scientist and the country of his origin whose field of work was elasticity.
- The word “Physics” comes from a Greek word. Name the word.
- The word science has come from a Latin verb. Name the verb.
- What is the meaning of the verb ‘Scientia’?
- Name the scientist and the country of his origin who received the Nobel Prize for his work on molecular spectra.
- What is the most incomprehensible thing about the world?
- Name a great scientist who gave the following comment on science.
- Which famous philosopher gave the following comments on science?
- Who discovered the electron?
- Who discovered neutron?
- Who gave the general theory of relativity?
- Who proposed the wave theory of light?
- Name four physics devices widely used in medical diagnosis.
- Name Indian-born scientist who received Nobel Prize for his discoveries in astronomy.
- Metaphysics is a science that is concerned with what?
- Which science is considered to be the mother of all sciences?
- Name the discovery made by S.N. Bose.
- Name the scientist and the country of his origin whose field of work was ‘cosmic rays’.
- What are the meaning of the Sanskrit word ‘Vijnan’ and the Arabic word ‘Ilm’?
- Name the Sanskrit equivalent word of Physics.
- Name the field of Physics in which India was a leading country in the sixties.
- Who discovered X-rays?
- Differentiate between Biological and Physical sciences?
- What is the relation between Physics and Technology?
- What is the relation between Physics and society?
- Is Science on speaking terms with humanities?
- What is the relation between Physics and Technology?
- Is Physics more of a philosophy or more of a mathematical science?
- Define Biophysics.
- Define Technology?
- Has imagination any role in Physics?
- Name a few aspects of your daily life in which you rely on the simplicity of nature.
Class 11 Physics Chapter 2 Important Extra Questions Units and Measurements
- If the size of the atom were enlarged to the tip of the sharp pin, how large would the height of Mount Everest be?
- What does the LASER mean?
- If the Universe were shrunk to the size of the Earth, how large would the Earth be on this scale?
- A research worker takes 100 careful readings in an experiment. If he repeats the same experiment by taking 400 readings, then by what factor will the probable error be reduced?
- What is the number of significant figures in 0.06070?
- Which of the following reading is most accurate?
- The density of a cube is calculated by measuring the length of one side and its mass. If the maximum errors in the measurement of mass and length are 3% and 2% respectively, then what is the maximum possible error in the measurement of density?
- The mass of a body as measured by two students is given as 1.2 kg and 1.23 kg. Which of the two is more accurate and why?
- Do the inertial and gravitational masses of ordinary objects differ in magnitude?
- Are S.I. units Coherent? Why?
- Do A.U. And Å represents the same magnitudes of distance?
- What does SONAR stand for?
- What is the atomic mass unit (a.m.u.)?
- Which is the most accurate clock?
- Write the S.I. units of the following physical quantities:
- What is the difference between mN, Nm, and nm?
- f x = a + bt + ct2 where x is in meter and t in seconds, what is the unit of c?
- Will the dimensions of a physical quantity be the same, whatever be the units in which it is measured? Why?
- Write the dimensions of:
- State the principle of homogeneity of dimensions?
- Which are the main types of errors in a physical measurement?
- Which one is large, the number of microseconds in a second or the number of seconds in a year?
- Do significant figures change if the physical quantity is measured in different systems of units?
- Suggest a distance corresponding to each of the following order of length:
- If the size of a nucleus is scaled up to the tip of a sharp pin, what roughly is the size of an atom?
- What do you mean by physical quantity?
- Define the unit of a physical quantity.
- Define one Candela.
- What is the advantage of choosing wavelength of light radiation as standard of length?
- Which type of phenomenon can be used as a measure of time? Give two examples of it.
- Find the number of times the heart of a human being beats in 10 years. Assume that the heartbeats once in 0.8s.
- Why it is not possible to establish a physical relation involving more than three variables using the method of dimensions?
- What is the difference between accurate and precise measurement?
- Pick up the most accurate and most precise measurement out of (a) 50.0 m, (b) s.oe m, (e) 5.00 cm, (f) 5.00 mm.
- Define one parsec.
- Define annual parallax.
- What arè the characteristics of a standard unit?
- What are the advantages of the S.I. system?
- Point out the measurable likely to create the maximum error in the following experimental measurement.
- Classify the physical quantities on basis of their dimensional formula.
- What are the limitations of dimensional analysis?
- Mankind has existed for about 106 years whereas the s. the universe is about 1010 years old. If the age of the universe is taken to be one day, how many seconds has mankind existed?
- State and explain the rule for finding the maximum possible error in a result.
- How do you represent very large and very small physical y quantities? Write the prefixes, multiple, submultiple, and their symbols in a tabular form.
- Explain the importance of reference frames in measurements.
- Briefly describe the various techniques to measure time.
- Explain the rules for finding significant figures in the sum, difference, product, and quotients of true numbers.
Motion in a Straight Line Class 11 Important Extra Questions Physics Chapter 3
- Can a moving body have relative velocity zero with respect to another body? Give an example.
- Can there be motion in two dimensions with acceleration in only one dimension?
- Is it true that a body is always at rest in a frame that is fixed to the body itself?
- Tell under what condition a body moving with uniform velocity can be in equilibrium?
- What does the speedometer records: the average speed or the instantaneous speed?
- Can an object be accelerated without speeding up or slowing down? Give examples,
- Is it possible to have the rate of change of velocity constant while the velocity itself changes both in magnitude and direction? Give an example.
- Which motion is exactly represented by Δs = vΔt?
- In which frame of reference is the body always at rest?
- What is common between the two graphs shown in figs, (a) and (b)?
- What is common between the two graphs shown in figs, (a) and (b)?
- What is meant by a point object in Physics?
- The displacement of a body is zero. Is the distance covered by it is necessarily zero?
- Which of the velocity or speed is measured by the speedometer of a vehicle?
- Can you think of a situation where a body falling under gravity has constant velocity? Give example.
- Give an example of a motion which even though is accelerated motion yet it is called uniform motion.
- How many-dimensional motion does the following have?
- When is the average velocity over an interval of time becomes equal to instantaneous velocity?
- A coolie carries a bag of luggage from one side of a platform to another side on the same platform. How far vertically the load is shifted?
- The displacement of a body is proportional to the square of time along a straight line. Is the body moving with constant velocity or constant acceleration?
- Prove that the average velocity of a particle over an interval of time is either smaller than or equal to the average speed of the particle over the same interval.
- Two trains each of the length 109 m and 91 m are moving in opposite directions with velocities 34 km h-1 and 38 km h-1 respectively. At what time the two trains will completely cross each other?
- Ambala is at a distance of 200 km from Delhi. Ram sets out from Ambala at a speed of 60 km h-1 and Sham set out at the same time from Delhi at a speed of 40 km h-1. When will they meet?
- A car travelling at a speed of 60 km h-1 on a straight road is ahead of a scooter travelling at a speed of 40 km h-1. How would the relative velocity be altered if the scooter is ahead of the car?
- Draw the position-time graphs for two objects initially occupying different positions but having zero relative velocity.
- A ball is thrown vertically upward with a velocity of 20 ms-1. It takes 4 seconds to return to its original position. Draw a velocity-time graph for the motion of the ball and answer the following questions:
- “It is the velocity and not the acceleration which decides the direction of motion of a body.” Justify this statement with the help of a suitable example.
- Two buses A and B starting from the same point move in a mutually perpendicular direction with speeds uA km h-1 and uB km h-1 respectively. Calculate the relative velocity of A w.r.t B.
- A draw velocity-time graph for a body which
- From a velocity-time graph, how do you calculate the average acceleration of a moving body?
- State whether the following two graphs in Fig. here represent the same type of motion or not. Name the motion of the particle.
- Draw the velocity-time graph for an object moving with uniform velocity. What does it show for t < 0?
Class 11 Physics Chapter 4 Important Extra Questions Motion in a Plane
- Under what condition |a + b| = |a| + |b| holds good?
- The sum and difference of the two vectors are equal in magnitude i. e. |a + b|=|a – b|. What conclusion do you draw from this?
- What is the minimum number of coplanar vectors of different magnitudes which can give zero resultant?
- When a – b = a + b condition holds good than what can you say about b?
- What is the magnitude of the component of the 9î – 9ĵ + 19k̂ vector along the x-axis?
- Can displacement vector be added to force vector?
- What is the effect on the dimensions of a vector if it is multiplied by a non-dimensional scalar?
- (a) What is the angle between î + ĵ and î vectors?
- What is the dot product of 2î + 4ĵ + 5k̂ and 3î + 2ĵ + k̂?
- What must be the value of ‘a’ in 2î + 2ĵ – ak̂ so that it is perpendicular to 5î + 7ĵ – 3k̂?
- Is finite rotation a vector quantity? Why?
- Is infinitesimally small rotation a vector quantity? Why?
- (a) Can the resultant of two vectors of different magnitudes be zero?
- A quantity has both magnitude and direction. Is it necessarily a vector? Why? Give an example.
- In a vector equation, all the quantities are of similar nature but their directions are different. Does it mean that the vector equation is necessarily incorrect? Electric current.
- Why vectors cannot be added algebraically?
- Fifty vectors each of magnitude 10 units are completely represented by the sides of a polygon in the same order. What will be the resultant?
- How will you prove that the given vectors are neither parallel nor perpendicular?
- Name two quantities that are the largest when the maximum height attained by the projectile is largest.
- A stone dropped from the window of a stationary railway carriage takes 2 seconds to reach the ground. At what time the stone will reach the ground when the carriage is moving with
- Can a particle accelerate when its speed is constant? Explain.
- (a) Is circular motion possible at a constant speed or at constant velocity? Explain.
- When the component of a vector A along the direction of vector B is zero, what can you conclude about the two vectors?
- Comment on the statement whether it is true or false “Displacement vector is fundamentally a position vector.’’ Why?
- Does the nature of a vector changes when it is multiplied by a scalar?
- Can the walk of a man be an example of the resolution of vectors? Explain.
- Explain under what conditions, the resultant of two vectors will be equal to either of them.
- Why the magnitude of the rectangular components of a vector can’t be greater than the magnitude of the vector itself?
- Can a flight of a bird be an example of the composition of vectors? Explain.
- Can commutative law be applied to vector subtraction?
- Write down the vector whose head is at (4, 3, 2) and whose tail is at (3, 2, 1).
- If A.B = A.C, is it safe to conclude that B = C?
- Define Tensor. Give example.
- How does a sling work?
- Why does a tennis ball bounce higher on hills than in plains?
- Two particles are moving with equal and opposite velocities in such a way that they are always at a constant distance apart. Calculate the time after which the particles return to their initial positions.
- Which one of the following is greater? (a) The angular velocity of the hour hand of a watch. (b) The angular velocity of the Earth around its own axis. Why
- A bomber in the horizontal flight drops a bomb when it is just above the target. Explain whether the bomb hits the target or misses it?
- What is the direction of the area of the vector?
- A ball is thrown horizontally and at the same time, another ball is dropped from the top of a tower with the same velocity.
- Three balls thrown at different angles reach the same maximum height (fig. given), then answer the following:
- When a car is driven too fast around a curve it skids outward. How would a passenger sitting inside explain the car’s motion? How would an observer standing by the roadside explain the event?
Class 11 Physics Chapter 5 Important Extra Questions Laws of Motion
- Why do we beat dusty blankets with a stick to remove dust particles?
- If you jerk a piece of paper from under a book quick enough, the book will not move, why?
- Why passengers are thrown outward when a bus in which they are travelling suddenly takes a turn around a circular road?
- Why a one rupee coin placed on a revolving table flies off tangentially?
- When the electric current is switched off, why the blades of a fan keep on moving for some time?
- A body of mass m is moving on a horizontal table with constant velocity. What is the force on the table?
- Will a person while firing a bullet from a gun experience a backward jerk? Why?
- What happens to the acceleration of an object if the net force on it is doubled?
- According to Newton’s third law of motion, every force is accompanied by an equal (in magnitude) and opposite (in direction) force called reaction, then how can a movement take place?
- Why does a swimmer push the water backward?
- Can a rocket operate in free space?
- Which of Newton’s laws of motion is involved in rocket propulsion?
- A passenger sitting in a bus at rest pushes it from within. Will it move? Why?
- Can a body in linear motion be in equilibrium? why?
- Can a force change only the direction of the velocity of an object keeping its magnitude constant?
- Two objects having different masses have some momentum. Which one of them will move faster?
- A book is lying on an inclined plane. Is some force of friction acting on the book?
- Write the S.I. units of force, momentum, and impulse.
- Why rockets are given conical shapes?
- Explain why jet planes cannot move in air-free space but rockets can move?
- A learner shooter fired a shot from his rifle and his shoulder got injured ¡n the process. What mistake did he commit?
- Newton’s first law of motion is the law of Inertia. Explain.
- An astronaut accidentally gets separated out of his small spaceship accelerating in inter-steller space at a constant rate of 100 ms-2. What is the acceleration of the astronaut at the instant after he is outside the spaceship?
- When a man jumps out of a boat, then it is pushed away. Why?
- Two hoys on ice-skates hold a rope between them. One boy is much heavier than the other. The lightweight boy pulls on the rope. How will they move?
- Explain why ball bearings are used in machinery?
- Why a horse has to apply more force to start a cart than to keep it moving? Explain.
- Sand is thrown on tracks or roads covered with snow. Explain why?
- Explain why is it difficult to move a cycle along a road with its brakes on?
- Explain how proper inflation of tires saves fuel?
- Explain how the man at rest in the middle of a pond of perfectly frictionless ice comes out by blowing air or splitting etc.?
- Give one argument in favor of the fact that frictional force is a non-conservative force.
- Why is it more dangerous to fall on frozen ice than on fresh snow?
- An astronaut in open space is away from his spaceship. How can he return to his ship?
- What is the difference between absolute and gravitational units of force?
- A disc of mass m is placed on a table. A stiff spring is attached to it and is vertical. To the other end of the spring is attached a disc of negligible mass. What minimum force should be applied to the upper disc to press the spring such that the lower disc is lifted off the table when the external force is suddenly removed?
- A force acting on a material particle of mass m first grows to a maximum value Fm and then decreases to zero. The force varies with time according to a linear law, and the total time of motion is tm. What will be the velocity of the particle at the end of this time interval if the initial velocity is zero?
- Sometimes we need to increase friction. Why? Given an example.
- Vehicles stop applying brakes. Does this phenomenon violate the principle of conservation of momentum?
- “Two surfaces if made extremely smooth, will have a very low value of friction between them.” Is the statement true? Justify your answer with two illustrations.
Class 11 Physics Chapter 6 Important Extra Questions Work, Energy and Power
- What is the source of the kinetic energy of the falling raindrops?
- A spring is stretched. Is the work done by the stretching force positive or negative?
- What is the type of collision when?
- (a) Give two examples of potential energy other than gravitational potential energy.
- What is the work done by the centripetal force? Why?
- (a) What is the work done by the tension in the string of simple pendulum?
- When an arrow is shot, wherefrom the arrow will acquire its K.E.?
- When is the exchange of energy maximum during an elastic collision?
- When a ball is thrown up, the magnitude of its momentum first decreases and then increases. Does this violate the conservation of momentum principle?
- In a tug of war, one team is slowly giving way to the other. What work is being done and by whom?
- A light and a heavy body have equal momentum. Which one of them has more K.E.?
- By using simple mechanical devices such as a lever, wedge, inclined plane, pulley, wheel, etc. we can do work even by applying small force. What makes it possible to do so?
- Two protons are brought closer. What is the effect on the potential energy of the system?
- Where is the energy of a vertically projected body maximum?
- Out of a pair of identical springs of force constants, 240Nm-1 one is compressed by 10 cm and the other is stretched by 10 cm. What is the difference in the potential energies stored in the two springs?
- What should be the angle between the force and the displacement for maximum and minimum work?
- Does the P.E. of a spring decreases/increase when it is compressed or stretched? Why?
- Can a body have momentum without energy?
- What type of energy is stored in the spring of the watch?
- Can a body have energy without momentum?
- In which motion, momentum changes but not the K.E.?
- Is the whole of K.E. lost in any perfectly inelastic collision?
- Can the P.E. of an object be negative?
- The momentum of a body is increased by 50%. What is the percentage change in its K.E.?
- What is the work done by Earth’s gravitational force in keeping the moon in its orbit in a complete revolution?
- What happens to its momentum? Is the law of conservation of momentum obeyed?
- In a thermal station, coal is used for the generation of electricity. Mention how energy changes from one form to the other. before it is transformed into electrical energy?
- Chemical, gravitational and nuclear energies are nothing but potential energies for different types of forces in nature. Explain this statement clearly with examples.
- What went wrong at the Soviet atomic power station at Chernobyl?
- A man can jump higher on the moon than on Earth. With the same effort can a runner improve his timing for a 100 m race on the moon as compared to that on Earth?
- How many MeV are there in a 1-watt hour?
- What is Newton’s experimental law of impact?
- Two masses one n times as heavy as the other have the same K.E. What is the ratio of their momenta?
- Two bodies A and B having masses mA and mB respectively have equal K.E. If pA and pB be their respective momenta, then prove that the ratio of momenta is equal to the square root of the ratio of respective masses. fc.
- How fast-moving neutrons can be quickly slowed down by passing through heavy water?
- Will water at the foot of the waterfall be at a different temperature from that at the top? If yes, explain.
- How is the kinetic energy of a particle related to the direction of motion of the particle? Can K.E. be negative?
- An automobile jack is employed to lift a heavyweight. The applied force is much smaller than the weight of the automobile. Can it be said that the work is done in less than the work done in? lifting the automobile directly through a height.
- What would be the effect on the potential energy of the system of two electrons brought closer?
- Can the kinetic energy be increased without the application of an external force? If yes, give an example.
- Mountain roads rarely go straight up the slope, but wind up gradually why?
- A truck and a car moving with the same K.E. are stopped by applying the same retarding force by means of brakes. Which one will stop at a smaller distance?
- A truck and a car are moving with the same K.E. on a straight road. Their engines are simultaneously switched off. Which one will stop at a lesser distance?
- A man rowing a boat upstream is at rest w.r.t. the shore. Is any work being done in this case?
- A body is heated by giving Q an amount of heat energy. Will its mass increase or decrease or remain constant? If it increases or decreases, then by how much?
Class 11 Physics Chapter 7 Important Extra Questions System of Particles and Rotational Motion
- Can the geometrical centre and C.M. of a body coincide? Give examples.
- How does the M.I. change with the speed of rotation?
- Under what conditions, the torque due to an applied force is zero?
- Is it correct to say that the C.M. of a system of n-particles is always given by average position vectors of the constituent particles? If not, when the statement is true?
- A cat is able to land on her feet after a fall. Which principle of Physics is being used by her?
- What is conserved when a planet revolves around a star?
- If no external torque acts on a body, will its angular velocity remain conserved?
- A body is rotating at a steady rate. Is a torque acting on the body?
- What is the other name for angular momentum?
- Out of two spheres of equal masses, one rolls down a smooth inclined plane of height h and the other is falling freely through height h. In which case, the work done is more?
- Many great rivers flow towards the equator. What effect does the sediment they carry to the sea have on the rotation of the Earth?
- Can the mass of a body be considered concentrated at its centre of mass for purposes of computing its rotational inertia?
- On what factors does the M.I. of a body depend?
- Should there exist mass at the location of C.M. of a system? Give an example.
- Should the C.M. of a body necessarily, lie inside the body? Explain.
- What is the position vector of C.M. of two particles of equal masses?
- If one of the particles is heavier than the other, to which side will their C.M. shift?
- What is an isolated system?
- Why do we prefer to use a wrench with a long arm?
- What is the rotational analogue of mass and force?
- What is the difference between the centre of gravity and C.M.?
- There are two spheres of the same mass and radius, one is solid and the other is hollow. Which of them has a larger moment of inertia about its diameter?
- What shall be the effect on the length of the day if the polar ice caps of Earth melt?
- If only an external force can change the state of motion of the C.M. of a body, how does it happen that the internal force of brakes can bring a vehicle to rest?
- What do you understand by a rigid body?
- Distinguish between internal and external forces.
- Two equal and opposite forces act on a rigid body. Under what conditions will the body (a) rotate, (Z>) not rotate?
- (a) Why is it easier to balance a bicycle in motion?
- A rod of weight W is supported by two parallel knife edges A and B and is in equilibrium in a horizontal position. The knives are at a distance d from each other. The C.M. of the rod is at a distance x from A. Find the normal reactions at knife edges A and B.
- What are the essential features of angular momentum?
- (a) What is the physical significance of M.I.?
- Define the radius of gyration of a body rotating about an axis.
- Derive the expression for the radius of gyration.
- Show that in the absence of an external force the velocity of the C.M. of a system remains constant.
- Define Torque. What is its physical significance?
- There is a stick half of which is wooden and half is of steel. It is pivoted at the wooden end and force is applied at the steel end at right angles to its length. Next, it is pivoted at the steel end and the same force is applied at the wooden end. In which case is the angular speed greater and why?
- How would you distinguish between a hard-boiled egg and a raw egg each spinning on a tabletop?
- Using the expression for power and K.E. of rotational motion, derive the relation τ = Iα.
- Equal torques are applied on a hollow cylinder and hollow sphere, both having the same mass and radius. The cylinder rotates about its axis and the sphere rotates about its diameter. Which one will acquire greater speed and why?
- A thin wheel can stay upright on its rim for a considerable time when rolled with a considerable velocity, while it falls from its upright position with the slightest disturbance, when stationary. Explain.
- Three homogeneous rigid bodies: a solid sphere, a solid cylinder and a hollow cylinder are placed at the top of an inclined plane. If they all are released from rest at the same elevation and roll without slipping, which one reaches the bottom first and which one reaches last?
Class 11 Physics Chapter 8 Important Extra Questions Gravitation
- What velocity will you give to a donkey and what velocity to a monkey so that both escape the gravitational field of Earth?
- How does Earth retain most of the atmosphere?
- Earth is continuously pulling the moon towards its center. Why does not then, the moon falls on the Earth?
- Which is greater out of the following:
- Where does a body weigh more – at the surface of Earth or in a mine?
- How is it that we learn more about the shape of Earth by studying the motion of an artificial satellite than by studying the motion of the moon?
- If the Earth is regarded as a hollow sphere, then what is the weight of an object below the surface of Earth?
- What is the formula for escape velocity in terms of g and R?
- What is the orbital period of revolution of an artificial satellite revolving in a geostationary orbit?
- Can we determine the mass of a satellite by measuring its time period?
- Is it possible to put a satellite into an orbit by firing it from a huge canon?
- What is the amount of work done in bringing a mass from the surface of Earth on one side to a point diametrically opposite on the other side? Why?
- Name one factor on which the period of revolution of a planet around the Sun depends.
- The gravitational potential energy of a body of mass m is -107 J. What is the energy required to project the body out of the gravitational field of Earth?
- Does the force of friction and other contact forces arise due to gravitational attraction? If not, what is the origin of these forces?
- Two satellites are at different heights. Which would have greater orbital velocity? Why?
- How much energy is required by a satellite to keep it orbiting? Neglect air resistance? Why?
- At noon the attractions of the Earth and Sun on a body on the surface of Earth are in opposite directions. But at midnight, they are in the same direction. Does a body weigh more at mid-night?
- What is geodesic?
- Why is G called a universal constant?
Class 11 Physics Chapter 9 Important Extra Questions Mechanical Properties of Solids
- Give an example of pure shear.
- What is an elastomer?
- What is breaking stress?
- What is the value of modulus of rigidity of a liquid?
- A wire is stretched to double its length. What is the value of longitudinal strain?
- Mention a situation where the restoring force is not equal and opposite to the applied force.
- What is a Cantilever?
- A wire is suspended from a roof but no weight is attached to the wire. Is the wire under stress?
- Why strain has no units?
- What is Poisson’s ratio?
- the bulk modulus of a perfectly rigid body?
- Why does spring balance shows wrong readings after they have been used for a long time?
- Name three physical properties which can have different values in different directions.
- What will happen to the potential energy if a wire is
- Which of the two materials (see figure here) would you choose for a car tire? Why?
- What are the factors due to which three states of matter differ from one’s Other?
- When we stretch a wire, we have to perform work Why? What happens to the energy given to the wire in this process?
- Why are the bridges declared unsafe after long use?
- Why are the springs made of steel and not of copper?
- A heavy machine is to be installed in a factory. To absorb vibrations of the machine, a block of rubber is placed between the machinery and the floor. Which of the two rubbers (A) and (B) of Figure would you prefer to use for this purpose? Why?
- Metal wires after being heavily loaded dop’\ regain their lengths completely explain why?
- Explain. Why spring balances show wrong readings after they have been, Used for a long time?
- Elasticity is said to be the internal property of matter. Explain.
- Define tensor physical quantities. Give an example.
- Define compressional stress.
- Define longitudinal or tensile stress.
- Define restoring force.
- Define longitudinal strain.
- Define volumetric strain.
- Define shear strain.
- State Hook’s law.
- Define bulk modulus.
- On what factors does the value of the coefficient of elasticity depend? Why it is of it three types?
- Why a hard wire is broken by bending it repeatedly in opposite direction?
- Elasticity has a different meaning in Physics and in our daily life. Why?
- The length of a Wire is increased by 16 cm when a weight of 5 kg is hung. If all conditions are the same, what will be the increase in its length when the diameter is doubled?
Class 11 Physics Chapter 10 Important Extra Questions Mechanical Properties of Fluids
- Why density increases with the fall of temperature?
- Why two holes are made to empty an oil tin?
- What is one torr of pressure?
- What are the values of systolic and diastolic blood pressure of a healthy human being?
- What is indicated by:
- Why water does not come out of a dropper unless its rubber head is pressed hard?
- What is 105 Nm-2 pressure called? What is the value of 1 torr?
- Why Hg is used in the barometer?
- The two thigh bones (femurs) each of cross-section area 10cm2 support the upper part of a human body of mass 40 Kg. Estimate the pressure sustained by the femurs.
- How can you check whether the barometer tube contains air or not?
- When air is blown in between the two balls suspended from a string such that they don’t touch each other, the balls come nearer to each other. Why?
- What is the effect of temperature on the viscosity of liquid?
- Why you can’t remove the filter paper from the funnel shown here by blowing from the narrow end?
- Why a raindrop falling freely does not acquire a high velocity?
- Why do the clouds float in the sky?
- A flask contains glycerine and the other one contains water. Both are stirred rapidly and kept on the table. In which flask will the liquid come to rest earlier than the other one and why?
- How does the viscous force between two layers of a liquid depend upon the relative velocity between two layers?
- Why firefighters have a jet attached to the head of their water pipes?
- People living in houses far removed from a municipal water tank often find it difficult to get water on the top floor even if it is situated lower than the level of water tank. Why?
- Why a small air bubble rises slowly through a liquid whereas the bigger one rises rapidly?
- Why more viscous mobile oil is used in summer than in winter in scooters?
- What are the values of Reynolds number (Ng) for different types of flows?
- A glass bulb is balanced by an iron weight in an extremely sensitive beam balance covered by a bell jar. What shall happen when the bell jar is evacuated?
- It is easier to swim in seawater than in river water. Why?
- Does Archimedes’ Principle hold in a vessel in free fall or in a satellite moving in a circular orbit?
- A block of wood floats in a pan of water in an elevator. When the elevator starts from rest and accelerates downward, does the 1 block floats higher above the water surface? What happens when the elevator accelerates upward? *
- The thrust on a human being due to atmospheric pressure is about 15 tons. How human being can withstand such an enormous thrust while it is impossible for him to carry a load of even one ton?
- Why are sleepers used below the rails? Explain.
- The passengers are advised to remove the ink from their f pens while going up in an airplane. Explain why?
- Why a sinking ship often turns over as it becomes immersed in water?
- Explain why a balloon filled with helium does not rise in the air indefinitely but halts after a certain height?
- A light ball can remain suspended in a vertical jet of water flow?
- In the case of an emergency, a vacuum brake is used to stop the train. How does this brake work?
- Why dust generally settles down in a closed room?
- What are buoyancy and the center of buoyancy?
- Centre of buoyancy coincides with the center of gravity?
Class 11 Physics Chapter 11 Important Extra Questions Thermal Properties of Matter
- The fact that the triple point of a substance is unique is used in modern thermometry. How?
- Is it possible for a body to have a negative temperature on the Kelvin scale? Why?
- (a) Why telephone wires are often given snag?
- There ¡s a hole in a metal disc. What happens to the size of the hole if the metal disc is heated?
- Milk is poured into a cup of tea and is mixed with a spoon. Is this an example of a reversible process? Why?
- The top of a lake is frozen. Air ¡n contact with it is at -15°C. What do you expect the maximum temperature of water in contact with the lower surface ice? What do you expect the maximum temperature of water at the bottom of the lake?
- How does the heat energy from the sun reaches Earth?
- Why does not the Earth become as hot as the Sun although it has been receiving heat from the Sun for ages?
- Why felt rather than air is employed for thermal insulation?
- What are the three modes of transmission of heat energy from one point to another point?
- Name suitable thermometers for measuring:
- Why a thick glass tumbler cracks when boiling liquid is poured into it?
- What is the basic principle of a thermometer?
- Out of mass, radius and volume of a metal ball, which one suffers maximum and minimum expansion on heating? Why?
- The higher and lower fixed points on a thermometer are separated by 160 mm. If the length of the mercury thread above the lower point is 40 mm, then what is the temperature reading?
- Two thermometers are constructed in the same way except that one has a spherical bulb and the other an elongated cylindrical bulb. Which of the two will respond quickly to temperature changes.
- Why a gas is cooled when expanded?
- Why two layers of cloth of equal thickness provide warmer covering than a single layer of cloth of double thickness?
- Why snow is a better heat insulator than ice?
- Why water in a metallic pot can be boiled quickly if the bottom of the pot is made black and rough than a highly polished surface?
- Pieces of glass and copper are heated to the same temperature. Why does the piece of copper feel hotter OIL touching?
- Why people in the desert wear heavy clothes?
- Why a wooden table fixed with iron nails become loose after some time?
- Wooden charcoal and a metal piece of the same dimension are heated in the same oven to the same temperature and then removed in the dark. Which one would shine more and why?
- What is the condition for the difference between the length of a certain brass rod and that of a steel rod to be constant at all temperature?
- Why fur coat is an insulator?
- Why does a bullet heat up when it hits a target?
- Why gas thermometers are more sensitive than mercury thermometers?
- Why the brake drum of an automobile gets heated up when the automobile moves down a hill at constant speed?
- Define Thermal conduction.
- On what factors does the amount of heat flowing from the hot face to the cold face depend? How?
- State Newton’s law of cooling and define the cooling curve. What is its importance?
- Explain why heat is generated continuously in an electric heater but its temperature becomes constant after some time?
- A woollen blanket keeps our body warm. The same blanket if wrapped around ice would keep ice cold. How do you explain this apparent paradox?
- A liquid is generally heated from below. Why?
- If a drop of waterfalls on a very hot iron, it does not evaporate fora long time. Why?
- On a hot day, a car is left in sunlight with all the windows closed. After some time, it is found that the inside of the car is considerably warmer than the air outside. Explain why?
- It takes longer to boil water with a flame in a satellite in gravitational field-free space, why? How it will be heated?
- Find γ for polyatomic gas and hence determine its value for a triatomic gas in which the molecules are linearly arranged.
- Food in a hot case remains warm for a long time during winter, how?
- You might have seen beggars sleeping on footpaths or in open in winter with their hands and knees pulled inside. Similarly dogs too curl while sleeping in winter. How does such action help anybody?
- Many people enjoy bathing below Kempty fall in Mussoorie, even though the water is quite cold, explain?
- Cycle, scooter handles and steering wheels of four-wheelers have plastic, rubber or cotton thread coverings. Why?
- Why metals like copper, iron, brass etc. are good conductors of heat whereas wood, cardboard, ply are not conductors of heat?
- House in Rajasthan made of stone and lime are cooler than those made of brick and cement why?
- Housing on hills are either made of wood or have wooden lining and walls. Why? Why people in plains where temperature variations are extreme winter and summer do not use-wooden house?
- People who own cars know well if they close all glass windows of the car park it in the Sun, it remains very hot inside the car even after sunset. To keep inside the car cooler insulating screens are put inside the car covering, the winds screen and curtains are pulled on the glass of windows, explain.
- What are the various properties of a thermometric substance?
- It is generally very cold after the hail storm than during or before it. Why?
- Why pendulums made of invar are used in clocks?
Class 11 Physics Chapter 12 Important Extra Questions Thermodynamics
- What type of process is Carnot’s cycle?
- Can the Carnot engine be realized in actual practice?
- A refrigerator transfers heat from a cold body to a hot body. Does this not violate the second law of thermodynamics?
- What is a heat pump?
- What forbids the complete conversion of work into heat?
- Does the internal energy of an ideal gas change in:
- What is the specific heat of a gas in an isothermal process and in an adiabatic process? Why?
- Can the temperature of an isolated system change?
- Can we increase the coefficient of performance of a refrigerator by increasing the amount of working substance?
- The door of an operating refrigerator is kept open in a closed room. Will it make the room warm or cool?
- How is the heat engine different from a refrigerator?
- What is the nature of the P – V diagram for isobaric and isochoric processes?
- Mention two essential characteristics of an ideal heat engine.
- Under that ideal condition can the efficiency of a Carnot engine be 100%?
- In summer, when the valve of a bicycle tube is removed, the escaping air appears cold. Why?
- When the air of the atmosphere rises up, it cools. Why?
- Why does gas get heated on compression?
- Which one among a solid, liquid, and gas of the same mass and at the same temperature has the greatest internal energy and which one has the least?
- Can two isothermal curves intersect each other?
- Does a gas work when it expands adiabatically is the source of energy?
- Name the forces ¡n a system that makes the process taking place in it irreversible in nature.
- Kelvin and Clausius’s statements of the Second law of thermodynamics are equivalent. Explain?
- Two identical samples of gas are expanded so that the volume is increased to twice the initial volume. However, sample number 1 is expanded isothermally while sample number 2 is expanded adiabatically. In which sample is the pressure greater? Why?
- No real engine can have an efficiency greater than that of a Carnot engine working between the same two temperatures. Why?
- Explain why two isothermal curves cannot intersect each other?
- What is the source of energy when gas does work when expands adiabatically?
- State and explain the zeroth law of thermodynamics?
- Why cannot a ship use the internal energy of seawater to operate the engine?
- A certain amount of work is done by the system in a process in which no heat is transferred to or from the system. What happens to the internal energy and the temperature of the system?
- If an electric fan is switched on in a closed room, will the air of the room be cooled? Why?
- Define coefficient of performance.
- State the principle of a refrigerator.
- Derive the expression for the coefficient of performance.
- What do you conclude about the coefficient of performance?
- Milk is poured into a cup of tea and is mixed with a spoon. Is this an example of a reversible process? Give reason.
- Explain whether the following processes are reversible?
Class 11 Physics Chapter 13 Important Extra Questions Kinetic Theory
- What does gas constant R signify? What is its value?
- What is the nature of the curve obtained when:
- The graph shows the variation of the product of PV with the pressure of the constant mass of three gases A, B and C. If all the changes are at a constant temperature, then which of the three gases is an ideal gas? Why?
- On the basis of Charle’s law, what is the minimum possible temperature?
- What would be the ratio of initial and final pressures if the masses of all the molecules of a gas are halved and their speeds are doubled?
- Water solidifies into ice at 273 K. What happens to the K.E. of water molecules?
- Name three gas laws that can be obtained from the gas equation.
- What is the average velocity of the molecules of a gas in equilibrium?
- A vessel is filled with a mixture of two different gases. Will the mean kinetic energies per molecule of both gases be equal? Why?
- Four molecules of a gas are having speeds, v1, v2, v3 and v4.
- The density of a gas is doubled, keeping all other factors unchanged. What will be the effect on the pressure of the gas?
- What is the average translational K.E. of an ideal gas molecule at a temperature T?
- Define the mean free path of a molecule.
- At what temperature, Charle’s law breaks down?
- A container has an equal number of molecules of hydrogen and carbon dioxide. If a fine hole is made in the container, then which of the two gases shall leak out rapidly?
- Two different gases have the same temperature. Can we conclude that the r.m.s? velocities of the gas molecules are also the same? Why?
- A gas enclosed in a container is heated up. What is the effect on pressure?
- What is an ideal gas?
- Define absolute zero.
- What do you understand by the term ‘Collision frequency’?
Why cooling is caused by evaporation?
On reducing the volume of the gas at a constant temperature, the pressure of the gas increases. Explain on the basis of the kinetic theory of gases.
Why temperature less than absolute zero is not possible?
There are n molecules of a gas in a container. If the number of molecules is increased to 2n, what will be:
Equal masses of O2 and He gases are supplied equal amounts of heat. Which gas will undergo a greater temperature rise and why?
Two bodies of specific heats S1 and S2 having the same heat capacities are combined to form a single composite body. What is the specific heat of the composite body?
Tell the degree of freedom of:
State law of equipartition of energy.
Explain why it is not possible to increase the temperature of gas while keeping its volume and pressure constant?
A glass of water is stirred and then allowed to stand until the water stops moving. What has happened to the K.E. of the moving water?
Why the pressure of a gas increases when it is heated up?
R.m.s. velocities of gas molecules are comparable to those of a single bullet, yet a gas takes several seconds to diffuse through a room. Explain why?
Calculate the value of the universal gas constant (R).
On what parameters does the λ (mean free path) depends?
Class 11 Physics Chapter 14 Important Extra Questions Oscillations
A particle has maximum velocity in the mean position and zero velocity at the extreme position. Is it a sure test for S.H.M.?
Imagine a situation where the motion is not simple harmonic but the particle has maximum velocity in the mean position and zero velocity at the extreme position.
We know that in S.H.M., the time period is given by
Two simple pendulums of equal lengths cross each other at the mean position. What is their phase difference?
A particle is in S.H.M. of amplitude 2 cm. At the extreme position, the force is 4N. What is the force at a mid-point i.e. midway between mean and extreme position?
Can & simple pendulum be used in an artificial satellite? Why?
What fraction of the total energy is potential energy when the displacement is one-half of the amplitude?
What fraction of the total energy is kinetic energy, when the displacement is one-half of the amplitude?
When a particle oscillates simply harmonically, its potential energy varies periodically. If v be the frequency of oscillation of the particle, then what is the frequency of vibration of P.E.?
A body of mass m when hung on a spiral spring stretches it by 20 cm. What is its period of oscillation when pulled down, and released?
A spring-mass system oscillating vertically has a time period T. What shall be the time period if oscillating horizontally?
The time period of a body executing S.H.M. is 0.05 s and the amplitude of vibration is 4 cm. What is the maximum velocity of the body?
A spring-controlled wristwatch is taken from Earth to Moon. What shall be the effect on the watch?
At what displacement, the P.E. of a simple harmonic oscillator is maximum?
What is the total energy of a simple harmonic oscillator?
Name the trigonometric functions which are suitable for the analytical treatment of periodic motions. ,
How is acceleration (a) related to the displacement (y) in S.H.M.?
At what position, the velocity of a particle executing S.H.M. is maximum?
What is Force constant (k)? What are its units in the S.I. system?
What ¡s the phase difference between displacement and velocity of a particle executing S.H.M.?
- Why does the body of a bus begin to rattle sometimes when the bus is accelerated?
- The displacement of a particle in S.H.M. may be given by x = A sin (ωt + Φ) Show that if the time t is increased by
- A hollow sphere is filled with water through a small hole in it. It is hung by a long thread and as water slowly flows out of the hole at the bottom, one finds that the period of oscillations first increases and then decreases. Explain why?
- A girl is swinging in the sitting position. How will the period ^ of the swing be changed if she stands up?
- At what displacement, a particle in S.H.M. possesses half K.E. and half P.E.?
- Explain why marching troops are asked to break their steps while crossing a bridge?
- What is the direction of acceleration at the mean and extreme positions of an oscillating simple pendulum?
- You are provided with a light spring, a meter scale, and a known mass. How will you find the time period of oscillation of mass attached to the spring without the use of a clock?
- Why does the time period of a pendulum change when taken to the top of a mountain or deep in a mine? Will clocks keep the correct time?
- What is the source of potential energy in a loaded elastic spring?
Class 11 Physics Chapter 15 Important Extra Questions Waves
- In a resonance tube, the second resonance does not occur exactly at three times the length at the first resonance. Why?
- What is the nature of ultrasonic waves and what is their frequency?
- Is the principle of superposition wave valid in the case of electromagnetic (e.m.) waves?
- A rod is clamped at one end and it is hit by a hammer at the other end
- Why do not we hear beats if the frequency of ìwo sounds is widely different?
- What causes the rolling sound of thunder?
- A tuning fork produces resonance in a closed pipe. But the ‘ same tuning fork is unable to, produce resonance in an open organ pipe of equal length. Why?
- Thick and big curtains are preferred in a big hall. Why?
- Why female voice is sweeter than that of a man?
- The frequency of the fundamental note of a tube closed at one end is 200 Hz. What will be the frequency of the fundamental note of a similar tube of the same length but open at both ends?
- A wave transmits energy. Can it transmit momentum?
- By how much the wave velocity increases for 1°C rise of temperature?
- Why the sound heard is more in carbon dioxide than in air?
- What is the relation between path difference and phase difference?
- Is it possible to have interference between the waves produced by two violins? Why?
- Here are the equations of three waves:
- (a) y (x, t) = 2 sin (4x – 2t)
- (b) y (x, t) = sin (3x – 4t)
- (c) y (x, t) = 2 sin (3x – 3t).
- Rank the waves according to their (A) wave speed and (B) maximum transverse speed, greatest first.
- Which physical quantity is represented by the ratio of the intensity of wave and energy density? Why?
- When are the tones called harmonics?
- What will be the effect on the frequency of the sonometer wire if the load stretching the sonometer wire is immersed in water?
- An organ pipe is in resonance with a tuning fork. If the pressure of air in the pipe is increased by a factor of 139, then how should the length be changed for resonance?
- Sound waves travel through longer distances during the night than during the day. Why?
- Water is being continuously poured into a vessel. Can you estimate the height of the water level reached in the vessel simply by listening to the sound produced?
- A sonometer wire resonates with a tuning fork. If the length of the wire between the bridges is made twice even then it can resonate with the same fork. Why?
- Doppler’s effect in sound is asymmetric. Explain.
- What is redshift?