Question

Two charged capacitors have their outer plates fixed and inner plates connected by a spring of force constant ' $k$'. The charge on each capacitor is $q$. Find the extension in the spring at equilibrium

• A. $\frac{q^{2}}{2 A \varepsilon_{0} k}$
• B. $\frac{q^{2}}{4 A \varepsilon_{0} k}$
• C. $\frac{q^{2}}{A \varepsilon_{0} k}$
• D. Zero

Answer 1

Answer: (A)

$F=k x=\frac{q^{2}}{2 A \varepsilon_{0}}$
$x=\frac{q^{2}}{2 A \varepsilon_{0} k}$