Question

Heat developed in half a minute in a resistance of 5 ohm is 15000 J. The current
through the resistor is?

Answer 1

Heat  = $I^{2}$RT

$I$ = current through resistor, R = resistance , T = time of observation(sec)

half minute = 1/2 minute = 1/2 × 60 seconds = 30 sec

15000 = $I^{2}$×5×30 = $I^{2}$×150

15000 =  $I^{2}$×150

15000/150 =  $I^{2}$

100 =  $I^{2}$

10 =  $I$

current is 10 A(ampere)