JAMB - Physics (2008 - No. 29)
An electric generator has e.m.f. of 240 V and an internal resistance of 1Ω if the current supplied by the generator is 20A when the terminal voltage is 220 V, find the ratio of the power supplied to the power dissipated?
11:1
1:11
12:11
11:12
Vysvetlenie
Power supplied = I\(^2\) R = 20\(^2\) X 1 = 400 W
Power dissipated = IV = 20 X 220 = 4400 W
(Power supplied)/Power dissipated = 4400 W / 400 W
= 11 / 1 or 11 : 1
Power dissipated = IV = 20 X 220 = 4400 W
(Power supplied)/Power dissipated = 4400 W / 400 W
= 11 / 1 or 11 : 1