Question
The length of a simple pendulum is increased four times to its previous value while the mass is doubled. What is the ratio of the new and previous time period of the pendulum?
NDA
General Ability
General Science
2025
NDA 2025 (Phase 1)
NDA General Ability Question (2025) — Solution
Options
- A. 3 : 1
- B. 2 : 5
- C. 2 : 1
- D. 3 : 2
Answer
C. 2 : 1
Step-by-step solution
The time period of a simple pendulum is given by T = 2 l g . The time period is independent of the mass of the bob. Given that the new length is l_2 = 4l_1. The new time period is T_2 = 2 l_2 g = 2 4l_1 g = 2 2 l_1 g = 2T_1. The ratio of the new and previous time period is T_2 T_1 = 2 1 . Answer: 2 : 1
Related: General Ability — General Science · All PYQ Banks