| ⇦ | 
| ⇨ |
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 first line in Lyman series has wavelength λ. The wavelength
- In atom bomb, the reaction which occurs is
- Excitation energy of a hydrogen like ion, in its first excitation state, is 40.8 eV.
- When 1 kg of ice at 0⁰C melts to water at 0⁰C, the resulting change in its entropy
- When three identical bulbs of 60 W-200 V rating are connected in series to a 200 V
Topics: Current Electricity
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- The first line in Lyman series has wavelength λ. The wavelength
- In atom bomb, the reaction which occurs is
- Excitation energy of a hydrogen like ion, in its first excitation state, is 40.8 eV.
- When 1 kg of ice at 0⁰C melts to water at 0⁰C, the resulting change in its entropy
- When three identical bulbs of 60 W-200 V rating are connected in series to a 200 V
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