engineering physics MCQ #969

A wire of resistance 5 ohms is stretched to twice its length. The new resistance is

engineering physics MCQ #969

  1. Question 1

    Q1. A wire of resistance 5 ohms is stretched to twice its length. The new resistance is

    • A) 10 ohms
    • B) 20 ohms
    • C) 5 ohms
    • D) 40 ohms

    Answer: 20 ohms

    Explanation: When the wire is stretched to twice its length, its area becomes half, so R = ρ(2l)/(A/2) = 4ρl/A = 4*5 = 20 ohms.