NTA Abhyas JEE Main2020PhysicsOscillationsPractice
The displacement of a damped harmonic oscillator is given by x t = e - 0 . 1 t   cos 10 π t + φ , where t is the time in seconds. The time taken for the amplitude of the oscillator to drop to half of its initial value is close to
Options
- A13   s
- B7 s
- C4 s
- D27 s
Correct answer
B. 7 s
Step-by-step solution
A 0 2 = A 0 e - 0 . 1 t ⇒ e - 0 . 1 t = 2 ⇒ 0 . 1 t = l n 2 t = ℓn 2 0 . 1 = 10 en 2 = 6 . 93 = 7 s