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 focal length of the objective of a terrestrial telescope is 80 cm
  2. what should be the velocity of an electron so that its momentum becomes equal
  3. A resistance of 20 ohm is connected to a source of an alternating potential V
  4. A Carnot engine takes heat from a reservoir at 627⁰C and rejects heat
  5. To measure the roughness of the surface of a material, which of the following microscope