MCQ
In damped oscillations, damping force is directly proportional to speed of oscillator. If amplitude becomes half of its maximum value in $1 \,s$, then after $2 \,s$ amplitude will be $\left(A_0-\right.$ initial amplitude)
  • $\frac{1}{4} A_0$
  • B
    $\frac{1}{2} A_0$
  • C
    $A_0$
  • D
    $\frac{\sqrt{3} A_0}{2}$

Answer

Correct option: A.
$\frac{1}{4} A_0$
a
(a)

$A=A_0 e^{-b t}$

Amplitude becomes half hence

$\frac{A_0}{2} A_0 e^{-b t}[t=1]$

$\therefore e^{-b}=\frac{1}{2}$

$\therefore \text { In two seconds }$

$A=A_0\left(\frac{1}{2}\right)^2$

$A=\frac{A_0}{4}$

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