Question

The potential difference between the terminals of an electric heater is 60 V when it draws a current of 4 A from the source. What current will the heater draw if the potential difference is increased to 120 V?​

Answer 1

Given that

V = 60V

I = 4A

R =

$\large\rm { \frac {V}{I} = \frac {60}{4} = 15Ω }$

When potential difference is increased to 120V

$\large\rm { I = \frac {V}{R} = \frac {150}{12} = 8A}$

The current through the heater becomes 8A

Answer 2

Given :-

• Potential energy, V = 60V.
• Current, I = 4A.

To find :-

The current through the heater.

Solution :-

According to ohm law,

.i.e.,

$\sf R = \dfrac{V}{I} = \dfrac{60}{4} = 15 \Omega$

When the potential difference is increased to 120V.

The current is given by,

$\sf current = \dfrac{V}{R} = \dfrac{120}{15 \Omega} = 8A$

Thus, the current through the heater becomes 8A.