⇦ | ![]() | ⇨ |
Masses of 3 wires of same metal are in the ratio 1:2:3 and their lengths are in the ratio 3:2:1. The electric resistances are in the ratio
Options
(a) (1:4:9)
(b) (9:4:1)
(c) (1:2:3)
(d) (27:6:1)
Correct Answer:
(27:6:1)
Explanation:
Mass = volume × density = A.l.d
Ald = m
Resistance R = ρl / A = ρl / (m/ld) = dρ (l²/m)
Now, R₂ / R₁ = (ρd / ρd) )(l₂² / l₁²) (m₁/m₂)
= (2/3)² × (1/2) = 2 / 9
⇒ R₂ = (2 / 9) R₁
Again R₃ / R₁ = (ρd / ρd) )(l₃² / l₁²) (m₁/m₃)
= (1/3)² × (1/3) = 1 / 27
⇒ R₃ = (R₁ / 27)
.·. R₁ : R₂ : R₃ = R₁ : (2/9) R₁ : (R₁/27) = 27 : 6 : 1
Related Questions:
- The drift velocity does not depend upon
- The dimension of 1/2ε₀E², where ε₀ is permittivity of free space and E is electric field
- A metal bar of length L and area of cross-section A is clamped between two rigid
- The depletion layer in the p-n junction region is caused by
- If a magnet is suspended at an angle 30⁰ to the magnetic meridian, the dip needle
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
Leave a Reply