Question

How much heat will an instrument of 14W produce in half an hour if it is connected to a battery of 70 W?

Answer 1

The heat produced by the instrument will be 420 J.

This can be calculated as follows:

• We know that Heat = V I T          (eq 1)

• Also, Power = V I                         (eq 2)

• From eq 1 and eq 2, we get,

        Heat = Power x T

• As per the question, Power = 14W and T = 30 sec

• Thus, Heat = 14 x 30

                           = 420 J