Processing math: 100%
Home / Aptitude Tests / Physics / When an alternating ...
When an alternating current given by I = 10sin (120π)t pass...

When an alternating current given by I = 10sin (120π)t passes through a 12Ω resistor, the power dissipated in the resistor is

A.

1200W

B.

600W

C.

120W

D.

30W

Correct answer is A

An a.c current is usually expressed as I = Io sin wt; and comparing this with the given current I = 10sin (120π)t, => Io = 10.
and power in an a.c circuit is given as:
P = I2R
= (102 x 12)
= 1200W