CBSE Class 9 Maths Chapter 1 MCQs – Rational & Irrational Numbers with Real Number Representation
CBSE Class 9 Maths Chapter 1 MCQs – Rational & Irrational Numbers with Real Number Representation
Class: 9
Subject: Mathematics
Chapter: 1 – Number Systems
Board: CBSE (Based on Latest NCERT Curriculum)
These Multiple Choice Questions (MCQs) are designed strictly as per the CBSE curriculum based on NCERT books and are ideal for CBSE Class 9 Mathematics examinations.
Subject: Mathematics
Chapter: 1 – Number Systems
Board: CBSE (Based on Latest NCERT Curriculum)
These Multiple Choice Questions (MCQs) are designed strictly as per the CBSE curriculum based on NCERT books and are ideal for CBSE Class 9 Mathematics examinations.
1. Which of the following is an irrational number?
Answer: C) √5
Explanation: √5 cannot be written in p/q form and its decimal expansion is non-terminating non-repeating.
Explanation: √5 cannot be written in p/q form and its decimal expansion is non-terminating non-repeating.
2. The decimal expansion of 7/20 is:
Answer: B) Terminating
Explanation: 7/20 = 0.35. Since denominator has only 2 and 5 as prime factors, decimal terminates.
Explanation: 7/20 = 0.35. Since denominator has only 2 and 5 as prime factors, decimal terminates.
3. Every irrational number is:
Answer: B) Real
Explanation: Real numbers include both rational and irrational numbers.
Explanation: Real numbers include both rational and irrational numbers.
4. √16 equals:
Answer: A) 4
Explanation: The principal square root of 16 is 4.
Explanation: The principal square root of 16 is 4.
5. 0.1010010001… is:
Answer: B) Irrational
Explanation: The decimal is non-terminating and non-repeating.
Explanation: The decimal is non-terminating and non-repeating.
6. If p/q has terminating decimal, then q has prime factors:
Answer: A) Only 2 or 5
Explanation: Terminating decimals occur only when denominator (in simplest form) has 2 and/or 5.
Explanation: Terminating decimals occur only when denominator (in simplest form) has 2 and/or 5.
7. √2 lies between:
Answer: A) 1 and 2
Explanation: √2 ≈ 1.414.
Explanation: √2 ≈ 1.414.
8. The product of a rational and irrational number is:
Answer: B) Irrational
Explanation: Example: 2 × √3 = 2√3 (irrational).
Explanation: Example: 2 × √3 = 2√3 (irrational).
9. √49 is:
Answer: A) 7
Explanation: Principal square root is positive.
Explanation: Principal square root is positive.
10. 0.333… equals:
Answer: A) 1/3
Explanation: Repeating decimals are rational numbers.
Explanation: Repeating decimals are rational numbers.
11. Which is a rational number?
Answer: C) 5/9
Explanation: It is in p/q form.
Explanation: It is in p/q form.
12. √3 is approximately:
Answer: A) 1.732
Explanation: √3 ≈ 1.732.
Explanation: √3 ≈ 1.732.
13. Sum of two irrational numbers is:
Answer: C) Sometimes rational
Explanation: √2 + (-√2) = 0 (rational).
Explanation: √2 + (-√2) = 0 (rational).
14. √0.25 equals:
Answer: A) 0.5
Explanation: √0.25 = √(1/4) = 1/2 = 0.5.
Explanation: √0.25 = √(1/4) = 1/2 = 0.5.
15. π is:
Answer: B) Irrational
Explanation: π is non-terminating non-repeating.
Explanation: π is non-terminating non-repeating.
16. √(9/16) equals:
Answer: A) 3/4
Explanation: √9/√16 = 3/4.
Explanation: √9/√16 = 3/4.
17. 2^0 equals:
Answer: B) 1
Explanation: Any non-zero number raised to power 0 equals 1.
Explanation: Any non-zero number raised to power 0 equals 1.
18. √8 can be simplified as:
Answer: A) 2√2
Explanation: √8 = √(4×2) = 2√2.
Explanation: √8 = √(4×2) = 2√2.
19. The set of real numbers includes:
Answer: C) Both rational and irrational
Explanation: Real numbers include all rational and irrational numbers.
Explanation: Real numbers include all rational and irrational numbers.
20. Which number lies on the number line between 1.4 and 1.5?
Answer: A) √2
Explanation: √2 ≈ 1.414, which lies between 1.4 and 1.5.
Explanation: √2 ≈ 1.414, which lies between 1.4 and 1.5.