Pakistan MCQs

Electric potential is a scalar measured in volts.
Potential difference drives charge movement in circuits.

Use v=c/n.
V=3.0×10^8/1.25 = 2.4×10^8 m/s.

Current is I=Q/t.
Its SI unit is the ampere.

Snell's law gives 1×sin30° = 1.5 sinr.
Sinr=0.5/1.5≈0.333.

Potential difference is V=W/Q.
One volt equals one joule per coulomb.

The critical angle satisfies sin c = 1/1.5.
C≈sin^-1(0.667)=41.8°.

Resistance relates voltage and current through Ohm's law.
Its SI unit is the ohm.

Power is reciprocal focal length in metres.
P=1/0.25 = 4 dioptres.

An ohmic conductor has V=IR under constant temperature and conditions.
Its V-I graph is linear through the origin.

Power is P=1/f.
P=1/(-0.50) = -2 D.

Series resistors carry the same current.
The voltage drops add to the source voltage.

Use 1/f=1/do+1/di.
1/di=1/10-1/30=1/15, so di=15 cm.