An electric lampis marked 220V,100W. It is used for 5 hours daily. Calculate---1) Its resistance while glowing. 2) energy consumed in kwh/day.

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Solution

Here,
P = 100 W
V = 220 volts
t = 5 hr
We know
P = V²/R
=> R = V²/P
=> R = 220²/100
=> R = 484Î©
P = 100/1000 kW = 0.1 kW
Energy consumed = power in kW Ã— time in hour
= 0.1 Ã— 5 = 0.5 kWh
The resistance while glowing = 484 Î©
Energy consumed / day = 0.5 kWh

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An electric lampis marked 220V,100W. It is used for 5 hours daily. Calculate---1) Its resistance while glowing. 2) energy consumed in kwh/day.

Here,P = 100 WV = 220 voltst = 5 hrWe knowP = V2/R=> R = V2/P=> R = 2202/100=> R = 484Î©P = 100/1000 kW = 0.1 kWEnergy consumed = power in kW Ã— time in hour = 0.1 Ã— 5 = 0.5 kWhThe resistance while glowing = 484 Î©Energy consumed / day = 0.5 kWh

Here,
P = 100 W
V = 220 volts
t = 5 hr
We know
P = V²/R
=> R = V²/P
=> R = 220²/100
=> R = 484Î©
P = 100/1000 kW = 0.1 kW
Energy consumed = power in kW Ã— time in hour
= 0.1 Ã— 5 = 0.5 kWh
The resistance while glowing = 484 Î©
Energy consumed / day = 0.5 kWh