Question

An electric device, which heats water by immersing a resistance wire in the water, generates 50 cal of heat per second when an electric potential difference of 12 V is placed across its leads. What is the resistance of the heater wire? (Note: 1 cal = 4.186 J)

Answer 1

0.69 ohm

Step-by-step explanation:

Heat generated per second, H = 50 cal/s

Potential difference, V = 12 V

Let R is the resistance of coil.

The formula for the heat is given by

`H = (V^(2))/(R)t`

`50* 4.186 = (12^(2))/(R)* 1`

R = 0.69 ohm