Question

A heating coil has a resistance $200\Omega$ . At what rate will heat be produced in it when a current of $2.5A$ flows through it.

Answer 1

Hint
First step is to figure out the known quantities ( in this case resistance and current ). After that we have to derive the formula for the power generated due to the resistance. After that we can put the given values in the equation and get the answer for the problem.

Complete step-by-step solution :Firstly we have to sort out what we have got :
The resistance of the heating coil : $200\Omega$
The reading of current flowing through it : $2.5A$
Step1: As heat is a form of energy and the rate of flow of energy is power, therefore we have to find the power of the heating coil. We have to assume the rate at which the heat is generated in the heating coil after the current flows : $P$
And the formula to give the Power generated due to resistance is : $P = {I^2}R$
Step 2: Therefore, we have to put all the given quantities in the formula and find the answer for the given question:
$P = {I^2}R \\\ P = {(2.50)^2} \times 200 \\\ P = 1250W \\\$
Therefore, the correct answer for the rate of heat would be $1250J/s$

Note:- We can express the power generated or the rate of produced heat in both $W$ and $J/s$ . There is no difference apart from the representation in both the cases. Power can be expressed for all kinds of energies like light, heat , motion etc.