The following four wires are made of the same material and wire and are at the same temperature. Which one of them has highest electrical resistance?
Correct answer: B. length = 50 cm, diameter = 0.5 mm
- A. length = 100 cm, diameter = 1 mm
- B. length = 50 cm, diameter = 0.5 mm
- C. length= 200 cm, diameter= 2 mm
- D. length= 300 cm, diameter= 2 mm
Explanation
R= l/r2. For highest resistance, l/r2 should be maximum, which is correct for option B.
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