Question

An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.​

Answer 1

Answer:

3600

Explanation:

Given, Resistance, R = 8Ω

Current, I = 15A

time, t = 2 hrs

According to Joule's law of heating, the heat developed in the resistor is given by:

H = $I^{2} Rt$

H =

Answer 2

Explanation:

Given parameters

The resistance of the electric heater (R) = 8 Ω

Current drawn (I) = 15 A

Time = 2 hrs

T = 120 min x 60

Time (T) = 7200 secs

The rate of heat produced by the device in terms of power is expressed as

P= I2R

P = 15 x 15 x 8

P = 1800 watt

Answer

P= 1800 watt