Physics - Current Electricity Question with Solution | TestHub

Given that

V = 200 V

m = 100g = 0.1 kg

$s=250 \mathrm{J} {\mathrm{kg}}^{-1}{\mathrm{K}}^{-1}$

$∆\theta =0.4 K$

C =?

The energy stored in the capacitor is given by

$U=\frac{1}{2}C{V}^2$

$=\frac{1}{2}C\times {\left(200\right)}^2$

$=2C\times {10}^4 \mathrm{J}$

The energy is used to heat up the block. Let$∆\theta$be the rise in temperature, then heat energy is given by

$O=ms∆\theta =0.1\times 250\times 0.4$

$= 10 \mathrm{J}$

Now,

$2C\times {10}^4=10$

$\Rightarrow C=\frac{10}{2\times {10}^4}=5\times {10}^{-4}$

$\therefore \mathrm{ }C=500 \mathrm{\mu F}$