When a current of 4.0 A passes through a certain resistor for 10 minutes, 2.88 x 104 J of heat are produced. Calculate:
(a) the power of the resistor.
(b) the voltage across the resistor.
(a), Here it is given,
I = 4 amp,
t = 10 min = 10 x 60 = 600sec, H = 2.88x104J
We Know that according to Joule's law of heating
H = I2RT
28800 = 42xRx600
R = 3ohms
We know that
P = I2xR
= 42x3
P = 48W
(b) Here we have to find the potential difference, V = ?
We know that
V = IR
V = 4x3
V = 12V