An electric room heater draws a current of 2.4A from the 120V supply line. What current will this room heater draw when connected to 240V supply line?

Answer:

First case:

Given,

Current, I = 2.4amp Voltage, V = 120V We know that,

V = IR

120 = 2.4 × R

R = 120/2.4 = 50 Ohm

Second case:

Given,

Voltage, V = 240 volt Resistance, r = 50 Ohm We know that,

V = IR

240 = I × 50

I = 4.8 amp