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

Related Questions:

1. If the momentum of electron is changed by P, then the de-Broglie wavelength
2. The unit of electric permittivity is
3. A slab consists of two parallel layers of two different materials of same thickness
4. Which one of the following electrical meter has the smallest resistance?
5. In a n-type semiconductor, which of the following statement is true?

Topics: Current Electricity (136)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends