Question

An electric current of 3 A passes through a wire of resistance $15\Omega$ . How much heat will be developed in 1 minute?

Answer 1

Step 1: Given data

The current passes through the resistance, $I=3A$ .

The value of the resistance is $R=15\Omega$.

Given time for heat development is $t=60seconds.$

Step 2: Joule's law of heating

1. Joule's law states that when a current I is flowing in a conductor of resistance R for a time T sec, then the produced heat on the conductor is directly proportional to the square of the electric current.
2. Joule's law is defined by the form, $H=I^{2}RT$ , where, Q is the produced heat on the conductor.

Step 3: Calculation of heat

Now applying Joule's law,

$$\begin{gathered} H=I^{2}RT=3^2\times 15\times 60 \\ orH=8100Joule. \end{gathered}$$

Therefore, $8100Joule$ heat will be developed in 1 minute.