Question

 What is the energy consumed by 4 electric heaters each of power 500 W when used for 15 minutes? 
a) 0.5KWh
b)5KWh
c)2KWh
d)30KWh​

Answer 1

Power=P=500W

Time=15min

Total power of 4heaters

$\\ \sf\longmapsto 4(500)=2000W$

Total Time=

$\\ \sf\longmapsto 4(15)=60min=1h$

We know

$\boxed{\sf E=Pt}$

E denotes to Energy

P denotes to power

t denotes to time

$\\ \sf\longmapsto E=2000(1)$

$\\ \sf\longmapsto E=2000J$

$\\ \sf\longmapsto E=2KwH$

Answer 2

Answer:

Power of each device, P=500 W=0.5 kW

Time for which the devices are used, t=10 hours

Thus energy consumed by 4 devices, E=4×P×t

E=4×0.500×10 kWh

⟹E=20 kWh