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Class 9

Chapter 11 Class 9 - Work and Energy (Term 2)

Last updated at June 8, 2019 by Teachoo

NCERT Question 20 Find the energy in kWh consumed in 10 hours by four devices of power 500 W each. Power of 1 device = 500 W Power of 4 devices = 4 Γ 500 W = 2000 W Time taken = 10 hours We know that Power = (πΈπππππ¦ ππππ π’πππ)/(ππππ π‘ππππ) Energy consumed = Power Γ Time taken = 2000 Γ 10 = 20000 Wh = 20000/1000 kWh = 20 kWh Energy consumed is 20 kWh