Question

100J of heat is produced each second in 4ohm resistance. Find the potential difference across the resistor

Answer 1

We know that,
Heat = V^2 × t / R
100J = V^2 × 1sec. / 4ohm
V^2 = 100J × 4ohm / 1sec.
V^2 = 400
V = ✓400
V = 20V

Answer 2

The resistor's potential difference given here is 20 V

Given:

Heat produced = 100 J  

Time = 1 second

Resistance across the resistor = 4 ohm

To find:

Potential resistance across the resistor

Solution:

We know that heating effect of electric current,

$H=I^{2} R T$

The above relation of the heating effect can also be written as,

$I^{2}=\frac{H}{R T}$

Here, I=5, and R=4 ohm

$\Rightarrow \text { According to ohm's law }=V=I R$

$V=5 \times 4=20 \ V$

Therefore, the resistor's potential difference is 20 V