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An electric bulb is rated as 50 W, 220 V. Calculate the energy consumed by the bulb in 20 minutes. Express your answer in kWh. |
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Answer» hat, an electric bulb is rated as 50 W, 220 V.We have to FIND the energy consumed by the bulb in 20 minutes. From above data we have, power (P) = 50W and voltage (V) = 220VPower is defined as work done upon TIME.Power = 50W = 50/1000 kW Energy is defined as the capacity of doing work. Energy = Power × timeBefore substituting the VALUES in above formula, CONVERT the time into seconds. To convert time into seconds, divide the given value by 60.Time = 20 min = 20/60 = 1/3 secNow, substitute the values in the above formulaEnergy = 50/1000 × 1/3Energy = 1/60 Energy = 0.017 kWTherefore, the energy consumed by the bulb in 20 minutes is 0.017 kW. |
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