Question

Derive expression for electric energy consumed in a device is term of V , I and t where V is potential difference applied to it ,I is the current drawn by it and t is the time for which current flows?

Answer 1

v=ir and I=v/r and r=v/i

Answer 2

Explanation:

For derivation we need to use formula of work done

W = Q/V

And P = W/t

Now,

P = QV/t

And V = IR

Therefore

P = QIR/t

Or P = I^2R.......(i)

Now we need to find formula for energy,

Energy = P x t

Now we need to use the value of equation (i)

Energy = I^2R x t

Energy = V x R x t /R^2

Energy = V^2 x t/R

Therefore,

Energy Consumption = V^2 x t/R

Where,

V be the the voltage

R be the resistance and

t be the time.