Oscillations - Result Question 47
51. The time period of a mass suspended from a spring is $T$. If the spring is cut into four equal parts and the same mass is suspended from one of the parts, then the new time period will be
(a) $2 T$
(b) $\frac{T}{4}$
(c) 2
(d) $\frac{T}{2}$
[2003]
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Answer:
Correct Answer: 51. (d)
Solution:
(d) $T=2 \pi \sqrt{\frac{m}{k}}$
When a spring is cut into $n$ parts
Spring constant for each part $=n k$
Here, $n=4$
$T_1=2 \pi \sqrt{\frac{m}{4 k}}=\frac{T}{2}$
