Question

The potential difference between the terminal of an electric heater is 60v when it draws a current of 4a from the source what currentwill the heater draw if the heaterdraw if the potential difference is increased to 120v

Answer 1

Given :
Potential Difference of heater = 60v
current I=4A

Resistance =R?
By Ohm's law :

V=IR
R=V/R
=60/4=15 ohms

Now if potential is increased to 120 V
I=?
V=IXR
I=V/R
=120/15
=8 A

Hence current drawn by heater is 8A

Answer 2

Answer:

The current through the heater becomes 8 A.

Explanation:

Given,

The potential difference between the terminals of an electric heater is 60 V.

Current of 4 A is drawn from the source.

To find: What current will the heater draw if the potential difference is increased to 120 V

Solution:

According to Ohm's law, Potential difference is directly proportional to current.

i.e V  $\propto$  I

or, V = iR

here, V = 60 V and i = 4 A

Substituting the values,

R = V / i = 60 / 4 = 15 Ω

Now, V is increased to 120 V.

Again using ohm's law,

i = V / R = 120 / 15 =  8 A

Therefore, The current through the heater becomes 8 A.