JEE MAIN - Physics (2003 - No. 49)
A sheet of aluminium foil of negligible thickness is introduced between the plates of a capacitor. The capacitance of the capacitor
decreases
remains unchanged
becomes infinite
increases
Paskaidrojums
The capacitancce of parallel plate capacitor in which a metal plate of thickness $$t$$ is inserted is given by
$$C = {{{\varepsilon _0}A} \over {d - t}}.\,\,\,\,\,$$
Here $$t \to 0\,\,\,\,\,\,$$ $$\therefore$$ $$C = {{{\varepsilon _0}A} \over d}$$
$$C = {{{\varepsilon _0}A} \over {d - t}}.\,\,\,\,\,$$
Here $$t \to 0\,\,\,\,\,\,$$ $$\therefore$$ $$C = {{{\varepsilon _0}A} \over d}$$