Two springs A and B `(k_(A)=2k_(B))` are stretched by applying forces of equal magnitudes at the four ends. If the energy stored in A is E, that in B is :

Options

A. E/4
B. E/2
C. E
D. 2E

Answer

B

Explanation

`U = 1/2 K_(A)x^(2) = 1/2K(F/K)^(2) = (F^(2))/(2K)`
Hence stored energy in inversely proportional to k .
` k _(A) = 2k_(B) rArr U_(B) = 2U_(A) = 2E ` .