Question

What is the function of dielectric in a capacitor?
a).Increase the capacitance
b).Decreases the capacitance
c).No change
d).None

Answer 1

A dielectric is an electric insulator that can be polarized by an applied electric field. Capacitor is used to store the energy in it and pass the energy after a while. Both the work of dielectric and capacitor is to hold the current or energy for some time, and then release it.

Complete answer:
A capacitor is an electronic component used to store and release electricity in a circuit. It also passes alternating current without passing direct current. It is an indispensable part of electronic equipment and thus is used in a wide range of electronic circuits.
A dielectric is basically an insulator. An insulator is used to stop the current from flowing. As both the job of capacitor and dielectric is to stop the current form flowing, placing a dielectric in between the plates of the capacitor will Increase the capacitance as a result.

Therefore, the correct option is option A which states that a dielectric will increase the capacitance when added in between the plates of a capacitor.

Additional information:
Capacitance is the effect of a capacitor. Capacitor is originally known as condenser or condensate. The capacitor does not dissipate energy like a resistor. When a dielectric is placed in the capacitor, the charges get accumulated as positive on one plate and negative on the other one. Eventually, the current through the circuit stops flowing when a dielectric is placed between the plates of the capacitor.

Note:
When a dielectric is introduced, the electric field is decreased, which decreases the voltage in turn. This internal change will result in increase in the capacitance. The net charge stored in the capacitor will be the same with or without the presence of dielectric. The only change is it stores the charge at low voltage.