In an electric circuit, a wire of resistance 10~\Omega is used. If this wire is stretched to a length double of its original value, the current in the circuit would become :
- A. half of its original value.
- B. double of its original value.
- C. one-fourth of its original value. ✓
- D. four times of its original value.
Correct Answer: C. one-fourth of its original value.
Explanation
When a wire is stretched to double its length, its cross-sectional area halves to maintain constant volume. Since resistance R = \rho(l/A), the new resistance becomes 4 times the original (40~\Omega). According to Ohm's law (I = V/R), the current will become one-fourth of its original value.
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