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Question
An electric bulb is rated 250 W, 230 V. Calculate:
- the energy consumed in one hour
- the time in which the bulb will consume 1.0 kWh energy when connected to 230 V mains.
Solution
Power P = 250 W,
t = 1 hr = 3600 S
- ∴ Energy consumed W = P × t
= 250 × 3600
= 900000 J
W = 9 × 105 J - 1.0 kWh = 36 × 105 J
∴ t in hours = `(36 xx 10^5)/(9 xx 10^5)`
= 4 hours
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