Question

derivation of joules law​

Answer 1

Answer:

P = VI

H = P × t = Vlt

But V = IR (ohm's law)

∴ H = I2Rt

(b) (a) Electric fuse

(b) Electric water heater

(c) H = 100J , R = 4 Ω , t = 1 sec .

H = I2Rt

I2 = H / R

Now, V = IR

V = 5 × 4

V = 20 V .

Answer 2

Answer:

check the attachment for all steps.