Chapter-8 Sequences and Series — Online MCQ Test
MATHS · Grade 11 · CBSE(NCERT)
Practice Chapter-8 Sequences and Series with a free chapter-wise online MCQ test.
This chapter covers: Arithmetic Progression (AP) - Geometric Progression (GP) - Common ratio - General term (an) - Sum of n terms (Sn) - Infinite GP - Arithmetic Mean (AM) - Geometric Mean (GM).
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-8 Sequences and Series — Important Questions & Answers
What is the common difference in the arithmetic progression 5, 8, 11, 14, ...?
- A. 3
- B. 5
- C. 2
- D. 4
Answer: A. 3
The common difference (d) is the difference between consecutive terms: 8 - 5 = 3.
The common difference (d) is the difference between consecutive terms: 8 - 5 = 3.
The general term of an AP is given by which formula?
- A. an = a + (n-1)d
- B. an = a + nd
- C. an = a × r^(n-1)
- D. an = a + d
Answer: A. an = a + (n-1)d
The nth term of an AP is given by an = a + (n-1)d, where a is the first term and d is the common difference.
The nth term of an AP is given by an = a + (n-1)d, where a is the first term and d is the common difference.
Find the 5th term of the AP: 3, 7, 11, 15, ...
- A. 17
- B. 19
- C. 21
- D. 23
Answer: B. 19
Using an = a + (n-1)d: a5 = 3 + (5-1)×4 = 3 + 16 = 19.
Using an = a + (n-1)d: a5 = 3 + (5-1)×4 = 3 + 16 = 19.
An AP has 50 terms with first term 2 and last term 101. What is the sum?
- A. 2500
- B. 2550
- C. 2600
- D. 2650
Answer: B. 2550
Sn = n(a + l)/2 = 50(2 + 101)/2 = 50(103)/2 = 2550.
Sn = n(a + l)/2 = 50(2 + 101)/2 = 50(103)/2 = 2550.
In a GP, if the product of 1st and 5th terms is 64, and the product of 2nd and 4th terms is also 64, what can be said about the 3rd term?
- A. It is 8
- B. It is 16
- C. It must be ±8
- D. It cannot be determined
Answer: C. It must be ±8
In a GP, a1 × a5 = a3² (since a1 × a5 = (a/r⁴) × (ar⁴) = a² and a2 × a4 = a3² = 64). Therefore a3 = ±8.
In a GP, a1 × a5 = a3² (since a1 × a5 = (a/r⁴) × (ar⁴) = a² and a2 × a4 = a3² = 64). Therefore a3 = ±8.