An electric heater is rated 1500 W. How much energy does it use in 10 hours?

We know that, \( P \ = \ \frac{W}{T} \)

Where,

Power rating of the heater,(P) = 1500 W = 1.5 KW

T = 10 hrs, \(\space \)
Work done = Energy consumed by the heater

\(\therefore energy \ consumed \ = \ Power \ × \ Time \)

\(\Rightarrow 1.5 \ × \ 10 \ = \ 15 \ kWh \)

Hence, the energy consumed by the heater in 10 hrs is 15 kWh.