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A wire of resistance R is stretched four times its length uniformly. Its new resistance will be

Correct answer: A. 16 R

  • A. 16 R
  • B. 4 R
  • C. R/4
  • D. R/16

Explanation

R = ρL/A L' = 4L ; A' = A/4 R' = ρ(4L) / (A/4) ==> R' = 16ρL / A R' / R = (16ρL / A ) / (ρL/A ) ==> R' / R = 16 R' = 16R

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About Current Electricity

Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.

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