# A fully charged capacitor has a capacitance C. It is discharged through a small coil of resistance…

Q: A fully charged capacitor has a capacitance C. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity S and mass m. If the temperature of the block is raised by  ΔT, the potential difference V across the capacitor is

(a) $\displaystyle \sqrt{\frac{2 m C \Delta T}{S} }$

(b) $\displaystyle \frac{ m C \Delta T}{S}$

(c) $\displaystyle \frac{ m S \Delta T}{C}$

(d) $\displaystyle \sqrt{\frac{2 m S \Delta T}{C}}$

Sol: $\displaystyle \frac{1}{2}C V^2 = m S \Delta T$
$\displaystyle V = \sqrt{\frac{2 m S \Delta T}{C}}$