Masses of 3 wires of same metal are in the ratio 1:2:3 and their lengths

Masses Of 3 Wires Of Same Metal Are In The Physics Question

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:

  1. A cricketer can throw a ball to a maximum horizontal distance of 100 m. With the same
  2. Pascal-second has the dimensions of
  3. A transformer having efficiency of 90% is working on 200 V and 3kW power supply
  4. B is doped in Si or Ge, then we will get
  5. The kinetic energy of α-particle emitted in the α-dacay of ₈₈Ra²²⁶ 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.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*