an electric heater consumes 3.6MJ when connected to a 250V supply for 40minutes find the power rating of the heater and the current taken from supply

Power rating of heater=1.5kw

Current taken from the supply=6A

Explanation:

Power (P) = Energy/Time

Where, electrical energy=3.6*10^6J and Time=40mins=40*60s

P=3.6*10^6J/40*60s

P=1500J/s or 1500watts

P=1.5kw

Current supply:

P=VI

Where, power (P) = 1500watts, Voltage supply (V) = 250volts, and current (I) = ?

Making current (I) the subject of the formula:

I=P/V

I=1500watts/250volts=6A

Therefore, current taken from the supply is 6A.