# 9th Class Computer Chapter 2 Binary System

## 9th Class Computer Chapter 2 Binary System Short And Simple Question & Answer

**Q. 1. What is number system?**

**Ans: **A set of values used to represent different quantities is known as number system. For example. a number system can be used to represent the number of students in a class.

**Q.2. What is machine language?**

**Ans:** A computer understands the language of 1s and Os only called machine language.

**Q.3. How does digital computer represent data?**

**Ans:** The digital computer represents all types of data in binary numbers. It includes audio. graphics. video, text, and numbers.

**Q.4. What do you mean by the base or radix of a number system?**

**Ans:** The number of digits used in any’ number system defines its base or radix. For example. base of decimal systems is 10 because it uses digits 0 to 9. Similarly, the base of binary system is 2. because it uses digits 0 and 1.

**Q.5. List three types of number systems?**

**Ans: **Three types of number systems are decimal number system, binary number system and hexadecimal number system.

**Q.6. What is the most common number system?**

**Ans:** Decimal number system is commonly used in our daily life. Its base is 10 and it consists of ten digits from Oto 9. These digits ca be used to represent any numeric value.

**Q.7. What is binary number system?**

**Ans:** Binary number system consists of two digits O and I and Its base is 2. Each digit or bit in binary number system can be 0 or 1. The position of each digit in binary number system- represents a power of base 2.

**Q.8. What is hexadecimal number system?**

**Ans:** Hexadecimal number system consists of 16 digits from 0 to 9 and A to F. The alphabets A to F represent decimal numbers from 10 to 15. The base of this number system is 16.

**Q.9. Define computer memory and writes its types.**

**Ans:** Computer memory is a physical device that can store data. The two types of computer memory are volatile memory and non-volatile memory.

**Q.10. What is volatile memory? Give an example.**

**Ans: **Volatile memory is a device that can store data as long as the power supply is connected to it. The contents of volatile memory are lost as the power supply is disconnected. Random Access Memory (RAM) is an example of volatile memory.

**Q.11. What is non-volatile memory? Given examples.**

**Ans:** Non-volatile memory is a device that stores data even if the power supply is not connected.

to it. Hard drive, flash drive and memory cards are examples of non-volatile memory. It is also

known as secondary storage.9th Class

**Q.12. Write three differences between memory and storage.**

**Ans: **Memory stores data temporarily but storage stores it permanently. Memory has high speed than storage. The capacity of memory is typically smaller than storage.

**Q.13. How is data represented in computer?**

**Ans:** The digital computers store data in binary form. Different types of data such as .text, picture, video, or applications are stored in the form of Os and 1s. All characters on the keyboard are associated with the codes known as ASCII code. It is a standard used to represent data in computer memory.

**Q.14. What Is ASCII?**

**Ans:** ASCII stands for American Standard Code for Information Interchange. It is a standard used to represent data in computer memory.

**Q.15. Write ASCII codes for any three characters.**

**Ans: **The ASCII code for 1 is 49. The ASCII code for + is 43. The ASCII code for@ is 64.

**Q.16. What is the use of storage devices?**

**Ans:** Storage devices ore used to store data and programs permanently. These devices are. nonvolatile and retain the contents even if the power is turned off.

**Q.17. Give some examples of storage devices.**

**Ans:** Some examples of commonly used secondary storage devices are hard disks, optical discs (CDs/DVDs), USB flash drives and memory cards.

**Q.18. What is Boolean algebra?**

**Ans:** Boolean algebra is the algebra of logic. It uses binary values, so it is also known as binary- algebra or logical algebra. Boolean algebra is used in the designing of logic circuits in computer. These circuits perform different logical operations.

**Q.19. What is Boolean proposition? Give example.**

**Ans:** A Boolean proposition is a sentence that can be true or false. For example. the sentence “Are you a student?” is a proposition because its result is true or false. However, the sentence “What is your address?” is not a proposition because its result is not in the form of true or false.

**Q.20. What do you mean by truth value?**

**Ans: **The possible value of true or false that can be given to a Boolean proposition is known as truth values. It Is given on the basis of truthfulness or falsity 9f the Boolean proposition.

**Q.21. What are logical operators? Write three names of logical operators.**

**Ans:** Logical operators are used to combine more than one Boolean proposition or negate a proposition. Three logical operators include AND, OR and NOT.

**Q.22. Define compound Boolean proposition?**

**Ans:** The Boolean proposition that consists of multiple propositions is known as compound

Boolean proposition.

**Q.23. Define logical expression?**

**Ans: **Logical expression is an expression in which some logical operator is applied to the Boolean

proposition. The result of logical expression Is true or false. The logical expression is also

known as Boolean expression.

**Q.24. What is the use of AND operator?**

**Ans:** The AND operator is used to connect two or more propositions. The compound Boolean proposition is true if all connected propositions are true. Its result is false result if any proposition is false. It can be denoted by a dot (.).

**Q.25. What Is the use of OR operator?**

**Ans: **The OR operator is used to connect two or more propositions. The compound Boolean proposition is true if any connected proposition is true. Its result is false result if all propositions are fals. It can be denoted by a plus (+).

**Q.26. W at Is the use of NOT operator?**

**Ans: **The NOT operator is used to negate a proposition; it reverses the result of a proposition. For example, if P = “Today is Friday” is true then NOT(P) will be false. It can be denoted by negation symbol(-).

**Q.27. What Is truth table?**

**Ans: **A truth table is used to check whether a proposition is true or false. It is typically used to check the truth value of a proposition in which logical operators are used.

**Q.28. What is commutative law of Boolean algebra?**

**Ans: **The commutative law states that the order of application of two separate propositions is not important. It means that the order in which two variables in a Boolean expression are calculated does not change its result.

**Q.29. What Is distributive law of Boolean algebra?**

**Ans:** The distributive law is the most important law in Boolean algebra. It involves in two operators AND and OR.

**Q.30. What Is identity law of Boolean algebra?**

**Ans: **The identity law works with two operators AND and OR. It states that a variable OR’ed with 0 False) is always equal to that variable. Similarly, a variable. AND’ed with 1 (True) is always equal to that variable.