Question

An electric heater consumes 4.4 kW power when connected with a 220 V line voltage then,Solve the given example.
(i) Calculate the current passing through the heater.
(ii) Calculate resistance of a heater.
(iii) Calculate the energy consumed in 2 hours.
(Ans : (i) 20 A (2) 11.Q (3) 3.168 x 107 W )

Answer 1

Power = 4.4 kW = 4400 W

Potential = 220 V

(i) ∵ P= V × I

∴ I = P/V

⇒ I = 4400/220

∴ I = 20 A

Hence, the current flowing through the conductor is 20 A.

(ii) Using Ohm's law,

V = I × R

∴ R = V/I

⇒ R = 220/20

∴ R = 11 Ω

Hence, the Resistance of the Heater is 11 Ω.

(iii) Energy consumed = Power in kW × time in hrs.

= 4.4 × 2

= 8.8 kWh.

= 8.8 × 3.6 × 10⁶ J

= 31.68 × 10⁶ J.

= 3.168 × 10⁷ J.

Hope it helps.