QQuestion
An electric iron rated 1100 W, 220 V is operated for 5 hours. Calculate:
(a) the minimum rating of the fuse required.
(b) the energy consumed in kWh.
(c) the cost of the energy consumed, if the rate is ₹10 per unit.
✓Answer
Given, power (P) = 1100 W, voltage (V) = 220 V and time (t) = 5 h.
(a) Operating current = \frac{\text{P}}{\text{V}} = \frac{1100}{220} = 5 A.
The fuse rating should be slightly higher than the operating current. Therefore, the minimum suitable fuse rating is 6 A.
(b) Energy consumed = Power × time
= 1100 × 5
= 5500 Wh = 5.5 kWh.
(c) Cost of energy consumption = 5.5 × ₹ 10 = ₹ 55.
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