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An electric iron draws power at 420 W and 180 W at its two settings, on a 220 V supply. By how much does the current at the higher setting exceed that at the lower setting?
AAbout 2.73 A
BAbout 0.55 A
CAbout 1.91 A
DAbout 1.09 A
Answer & Solution
Correct answer: D. About 1.09 A
1. The current at any setting is $I = P/V$ on a fixed 220 V supply.
2. High setting: $I_1 = 420/220 \approx 1.91\,\text{A}$.
3. Low setting: $I_2 = 180/220 \approx 0.82\,\text{A}$.
4. The question asks how much the high current exceeds the low one.
5. Difference $= 1.91 - 0.82 = 1.09\,\text{A}$.
6. Trap C (1.91) is only the high current; trap D (2.73) adds the two currents instead of subtracting; trap B (0.55) halves the answer.
_Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 4 Electricity "Electricity", p.64_
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