| ⇦ | 
| ⇨ |
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: - Maximum range for a projectile motion is given as R. The maximum height will be
- The electirc field in a certain region is acting radially outward and is given by E=Ar.
- Two charges each equal to 2µ C are 0.5m apart. If both of them exist inside vacuum
- A gas is suddenly expanded such that its final volume becomes 3 times
- The physical quantities not having same dimensions are
Topics: Current Electricity
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Maximum range for a projectile motion is given as R. The maximum height will be
- The electirc field in a certain region is acting radially outward and is given by E=Ar.
- Two charges each equal to 2µ C are 0.5m apart. If both of them exist inside vacuum
- A gas is suddenly expanded such that its final volume becomes 3 times
- The physical quantities not having same dimensions are
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