Question

what voltage must be applied to a 6.4-ohm lamp filament to develop 20 amperes of current?

Answer 1

E = IR = 6.4 * 20

Answer 2

if the 5-ohm heater in problem 15 is placed with a 15-ohm heater, what current will the 15-ohm heater draw from the same power supply?

Answer 3

ummm. E = IR ?
This time find I.