# In the given figure the capacitor of plate area A is charged upto charge q. The ratio of elongations…

Q: In the given figure the capacitor of plate area A is charged upto charge q. The ratio of elongations (neglect force of gravity) in springs C and D at equilibrium position is

(a) $\displaystyle \frac{k_1}{k_2}$

(b) $\displaystyle \frac{k_2}{k_1}$

(c) $\displaystyle k_1 k_2$

(d) $\displaystyle \sqrt{ \frac{k_1}{k_2}}$

Ans: (b)

Sol:

Force acting between plates of capacitor is attractive & it is

$\displaystyle F = \frac{q^2}{2 \epsilon_0 A}$

$\displaystyle k_1 x_1 = k_2 x_2$

$\displaystyle \frac{x_1}{x_2} = \frac{k_2}{k_1}$