Which method can increase the capacitance of a capacitor?

Choosing a dielectric with a higher dielectric constant is the correct method to increase the capacitance of a capacitor because capacitance is directly related to the properties of the dielectric material used. The capacitance ( C ) of a parallel-plate capacitor is given by the formula:

[ C = \frac{\varepsilon A}{d} ]

where ( C ) is the capacitance, ( \varepsilon ) is the permittivity of the dielectric material (which incorporates the dielectric constant), ( A ) is the area of the plates, and ( d ) is the separation between the plates.

When a dielectric with a higher dielectric constant is used, it increases ( \varepsilon ), which in turn increases the capacitance. A higher dielectric constant allows the capacitor to store more charge for the same voltage, thereby increasing the energy storage capability.

The other options do not effectively increase capacitance. Using a thicker dielectric layer would actually increase the distance ( d ), which would decrease capacitance since capacitance and distance are inversely related. Increasing the distance between plates also increases ( d ) and, similarly, decreases capacitance. Reducing the voltage across the plates does not affect the physical structure or material properties of the capacitor