Question

If the time period of a pendulum is $25s$. What is the frequency of the pendulum?

• A. $4\times {10}^{-2}Hz$
• B. $4\times {10}^{-1}Hz$
• C. $25\times {10}^{-2}Hz$
• D. $2\times {10}^{-2}Hz$

Answer 1

Answer: (A)

$4\times {10}^{-2}Hz$

That time period ($T$) of an oscillating body, like a pendulum, is the time spent in completing one full oscillation. The frequency ($f$) is the number of oscillations performed in one second. Mathematically, the frequency is the reciprocal of the time period. If $T=25$ seconds then $f=\frac{1}{25}$ i.e. $4\times {10}^{-2}Hz$