Question

A heating element of a hot plate, on an electric
cooking range, draws 12A from 240V supply. How
many kWh of energy will be consumed in one hour
and 15 minutes:
(1) 1.2 (2) 3.6
(3) 6.0 (4) 7.2

Answer 1

W= V x I

   = 240 x 12

   = 2880

   = 2.88 kW  

Power consumed in 1 hr and 15 min:  

• power consumed in 1 hr= 2.88 kWh  

• power consumption in 15 min(= 0.25 hr)  

= 2.88 x 0.25 kWh

= 0.72 kWh  

TOTAL POWER CONSUMPTION = 2.88+0.72

= 3.6 kWh

= 3.6 unit