Question

A bulb is rated at 5.0 volt, 100 mA. Calculated its (i) power (ii) resistance.

Answer 1

v=ir therefore R=50ohm
p=V^2/R=25/50=1/2

Answer 2

1000mA = 1A

So, 100mA = 100/1000 = 0.1A

Potential difference = 5V (given)  

Resistance = V/I = 5/0.1 = 50 Ohm

Power = I x I x R = 0.1 x 0.1 x 50 = 0.5 Watt.

THANKS.

HOPE THIS HELPS YOU.