Question

An electric heater is rated 220 V; 11 A. Calculate the power consumed if the heater is operated at 200 V.

Answer 1

Given: Voltage (V₁) = 220 V

Current (I₁) = 11 A

Resistance (R) = `V_1/I_1`

= `220/11`

= 20 Ω

Now, calculate the power at operating voltage (V₂) = 200 V:

By using the formula for power:

P₂ = `V_2^2/R`

= `(200)^2/20`

= `40000/20`

= 2000 W

∴ The power consumed at 200 V is 2000 W (or 2 kW).