Two wires of equal length and equal diameter and having resistivities ρ₁ and ρ₂

⇦

⇨

Two wires of equal length and equal diameter and having resistivities ρ₁ and ρ₂ are connected in series. The equivalent resistivity of the combination is

Options

(a) ρ₁+ρ₂/2
(b) ρ₁+ρ₂
(c) ρ₁ρ₂/ρ₁+ρ₂
(d) √ρ₁ρ₂

Correct Answer:

ρ₁+ρ₂/2

Explanation:

The resistance of two wires are

R₁ = ρ₁ (l / A) and R₂ = ρ₂ (l / A)

Now, equivalent resistance of series connection of wire

Req = R₁ + R₂ = ρ₁ (l / A) + ρ₂ (l / A) = (l / A) (ρ₁ + ρ₂)

The equivalent resistance Req can be given by Req = ρ(eq) (l / A)

⇒ ρ(eq) (l / A) = (l / A) (ρ₁ + ρ₂)

Hence, ρ(eq) = (ρ₁ + ρ₂) / 2

Related Questions:

1. A charged particle experiences magnetic force in the presence of magnetic field.
2. Two vessels separately contain two ideal gases A and B at the same temperature,
3. A spring of spring constant 5 x 10³ N/m is stretched initially by 5 cm
4. The unit of thermal conductivity is
5. Let A = i Acosθ +j B sinθ be any vector.Another vector B which is normal to A is

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