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. A liquid wets a solid completely. The meniscus of the liquid in a sufficiently long
  2. An experiment takes 10 minutes to raise temperature of water from 0⁰C to 100⁰C
  3. Magnetic induction produced at the centre of a circular loop carrying current is B.
  4. Nuclear fission is not found in
  5. To demonstrate the phenomenon of interference, we require two sources which emit