Question 510: Electrostats & Capacitance

Question

The function of dielectric in a capacitor is

Accepted Answer

The correct answer is Option A.
Here's why:
When a dielectric is inserted between the plates of a capacitor, the dielectric material becomes polarized. This polarization creates an electric field that opposes the field due to the charges on the plates.
As a result, the effective electric field inside the capacitor is reduced. Since the potential difference (voltage) across the capacitor is related to the electric field by:
$$V = E \cdot d$$
(where $$d$$ is the separation between the plates), reducing the electric field $$E$$ also reduces the effective potential difference $$V$$ between the plates.
With a lower effective potential difference for the same amount of charge, the capacitance, defined by
$$C = \frac{Q}{V},$$
increases. This explains why the dielectric increases the capacitance rather than decreasing it.
So, Option A, "to reduce the effective potential on plates," correctly describes the role of a dielectric in a capacitor.

Answer

to reduce the effective potential on plates.

Answer

to increase the effective potential on plates.

Answer

to decrease the capacitance.

Answer

to reduce the plate area of capacitor.

Electrostats & Capacitance

The function of dielectric in a capacitor is

Choose the correct answer: