Electrostatic Potential and Capacitance - Result Question 39
41. In a parallel plate capacitor, the distance between the plates is $d$ and potential difference across the plates is V. Energy stored per unit volume between the plates of capacitor is
(a) $\frac{Q^{2}}{2 V^{2}}$
(b) $\frac{1}{2} \varepsilon_0 \frac{V^{2}}{d^{2}}$
(c) $\frac{1}{2} \frac{V^{2}}{\varepsilon_0 d^{2}}$
(d) $\frac{1}{2} \varepsilon_0 \frac{V^{2}}{d}$
[2001]
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Answer:
Correct Answer: 41. (b)
Solution:
- (b) Energy stored per unit volume
$=\frac{1}{2} \varepsilon_0 E^{2}=\frac{1}{2} \varepsilon_0(\frac{V}{d})^{2}=\frac{1}{2} \varepsilon_0 \frac{V^{2}}{d^{2}}(\because E=\frac{V}{d})$
