JAMB - Physics (1998 - No. 39)
Electricity is supplied to a school along a cable of total resistance 0.5\(\Omega\) with the maximum current drawn from the mains as 100A. The maximum energy dissipated as heat for 1 hr is
3.6 x 103J
5.0 x 103J
3.0 x 105J
1.8 x 107J
Giải thích
Elect. energy = I2Rt
= 100 x 100 x 0.5 x 3600
= 1.8 x 107J
= 100 x 100 x 0.5 x 3600
= 1.8 x 107J