Current Electricity · Class 12 · CBSE · Science Physics
A uniform wire of resistance R is stretched uniformly to double its original length. The new resistance of the wire will be:
Practice question from Current Electricity (Class 12 · CBSE · Science Physics), with the correct answer and a step-by-step solution.
medium · MCQ · Q-89F347
A uniform wire of resistance is stretched uniformly to double its original length. The new resistance of the wire will be:
- A.2R
- B.4RCorrect answer
- C.R/2
- D.R/4
Solution
When a wire is stretched without changing its mass, its volume remains constant. Since , the resistance is directly proportional to the square of the length (). If length is doubled, resistance becomes times the original value.
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