Resistance and Power - Technical MCQs

Q1:

How many amps are used by a 100 watt, 120 volt light bulb?

A 1.2 amps

B 12000 amps

C 830 mA

D 12 amps

ANS:C - 830 mA

W=100 watt
V=120 volt
I= ?

Ans: R=v^2/w.
=(120*120)/100,
=144 ohm.
I= V/R.
=120/144.
I= 0.83A.
I=830mA.