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 charged particle enters a uniform magnetic field with a certain speed at right angles
  2. A proton is projected with a speed of 3×10⁶ m/s horizontally from east to west.
  3. We get Balmer series when electron comes from
  4. Find the right condition(s) for Fraunhofer diffraction due to a single slit.
  5. Three unequal resistors in parallel are equivalent to a resistance 1 Ω.