Physics U21, U22, U23

Electric field strength is force per unit charge.

E = -v/d only for parallel fields. (potential gradient)

Point charge = Radial field

To charge a capacitor, work is done. Lesser the capacitance, more is the work done.

Capacitors are used to store energy.

C = Q/V

W = 1/2 VQ

t = RC (time constant)

t proportional to R --> More R, less I, so time taken increases.

t proportional to C --> More C, more Q, so time taken increases.

Q. Define capacitance of the capacitor.

Capacitor stores electrical energy by separating positive and negative charges. This electric energy creates potential difference as output. C = Q/V, where Q =  charge on 1 plate, and V = potential difference between both the plates.

Q. Explain what is meant by the capacitance of a parallel plate capacitor.

Capacitance of parallel plate capacitor is the charge stored in one plate divided by the voltage applied between both the plates. C = Q/V.