NCERT - Science

Book: NCERT - Science

Chapter: 12. Electricity

Subject: Physics - Class 10th

Q. No. 16 of Exercise-Pg-221

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16

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

(i) For TV set:

Power, P= 250W=


Time, t = 1 h


So, Electric energy, E= P x t = 0.25Kw x 1 h = 0.25 kWh


(ii) For toaster:


Power, P= 250W=


Time, t= 10 min=


So, Electric energy, E= P x t= 1.2 kW x = 0.20kWh


From the above calculations, it is clear that the TV set uses more energy (0.25 kWh) whereas toaster uses less energy (0.20 kWh).


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