JAMB - Physics (2003 - No. 38)
When an alternating current given by I = 10sin (120π)t passes through a 12Ω resistor, the power dissipated in the resistor is
1200W
600W
120W
30W
Giải thích
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
and power in an a.c circuit is given as:
P = I2R
= (102 x 12)
= 1200W