Question

400 joules of heat is produced in 4 second in a 4Ω resistor. find the potential difference across a resistor.

Answer 1

We know that
H=V'2/R×T
H×R/T=V'2
400×4/4=V'2
400=V'2
√400=V
V=20 Volt.

Answer 2

We know that


∴ t=4,H= 400, R=4 and v= ?

Joule's law of heating

H = (V² t) / R
V² =H×R/T
V² = 400×4/4
V² = 400
V=√400
=> V=20 Volt.

regard u