Question

The potential difference between the terminal of an electrical heater is 60v when it draw a current 4A fron the source. What current will the heater draw if the potential difference is increased to 120v?

Answer 1

The current through the heater is 8 A if potential difference is increased to 120 V.

Explanation:

• According to Ohm's Law, the potential difference (Voltage) is directly proportional to the current flowing through a conductor.

That is, V ∝ I

⇒ V = IR where R is the constant of proportionality called resistance.

• In this case, given voltage = 60 V and current = 4 A. To find the current, first find the constant of proportionality, resistance of the heater.

R = V/I = 60/4 = 15 ohm

• If the potential difference is increased to 120 V, find the current flowing through it.

I = V/R = 120/15 = 8 A