Question

derive an expression for electric energy consumed in a device in terms of V, I and t, where V is thepotential difference applied to it, I is the current drawn by it and t is the time for which the current flows.

Answer 1

We know

W = Q*V ..............(1) where W = Work done, Q = flow of charges and V = potential difference

We also know

Current I = Q/t where Q = flow of charges and t = time

= Q = It............(2)

putting value of Q from equation (2) to (1)

Work done or energy consumed = I*V*t

Answer 2

Answer:

Explanation:

To Derive :-

An expression for electric energy consumed in a device in terms of V, I and t.

Derivation :-

We know that work done = W = QV

Therefore, P = W/t

Now, P = QV/t

⇒ V = IR

⇒ P = (Q/t)IR = I²R

⇒ Energy = P × t

⇒ Energy = I²R × t

⇒ Energy = (V/R²) × R × t

⇒ Energy = (V²/R) × t

⇒ Energy = V²/R × t

Hence, Derived

Where, V = voltage

R = Resistance

t = time