Question

b) An electric heater is rated 200 W. How much energy does it use in 5 hours ?t​

Answer 1

Answer:

Time for which the heater is used t=10 hours =10×3600 s =36000 s

Energy consumed by the heater E=P×t where P is the power of the heater

∴ E=(1500) W ×36000 s

⟹E=5.4×10

7

J

E=15 kWh (∵1kWh=3.6×10

6

J)

Answer 2

Answer:

Time for which the heater is used t=10 hours =10×3600 s =36000 s

Energy consumed by the heater E=P×t where P is the power of the heater

∴ E=(1500) W ×36000 s

⟹E=5.4×10

7

J

E=15 kWh (∵1kWh=3.6×10

6

J)