Navigate

A wire of resistance 4 ohm is stretched to twice its original length.

A wire of resistance 4 ohm is stretched to twice its original length. The resistance of stretched wire would be

Options

(a) 4Ω
(b) 8Ω
(c) 16Ω
(d) 2Ω

Correct Answer:

16Ω

Explanation:

Resistance R = ρℓ / A

ℓ’ = 2 ℓ ⇒ A’ = A / 2

R’ = ρ [2 ℓ / (A / 2)] = 4R = 4 × 4Ω = 16Ω

NEET2013
admin:

Related Questions

  1. The moment of inertia of a thin uniform rod of mass M and length L about an axis
  2. If the volume of a block of aluminium is decreased by 1%, the pressure
  3. The difference in the lengths of a mean solar day and a sidereal day is about
  4. A body starts from rest with an acceleration of 2 m/s². After 5 second,
  5. The process of adding impurities to the pure semiconductor is called