Question

16. Which uses more energy, a 250 W TV set in 1 hr, or a 1200 W toaster in 10 minutes?



17. An electric heater of resistance 82 draws 15 A from the service mains 2 hours.
Calculate the rate at which heat is developed in the heater.​

Answer 1

Answer:

16.answer:

Energy consumed by the TVset = 250*3600 =9*105J ∴ Energy consumed by a toaster = 1200 × 600 = 7.2× 105J ∴ the energy consumed by a 250 W TV set in 1 h is more than the energyconsumed by a toaster of power 1200 W in 10 minutes.

17.answer:

An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater. Therefore, heat is produced by the heater at the rate of 1800 J/s.