/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 39 Two rods of length \(L_{1}\) and... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Two rods of length \(L_{1}\) and \(L_{2}\) are made of materials whose coefficients of linear expansion are \(\alpha_{1}\) and \(\alpha_{2}\). If the difference between the two lengths is independent of temperature. (A) \(\left(L_{1} / L_{2}\right)=\left(\alpha_{1} / \alpha_{2}\right)\) (B) \(\left(L_{1} / L_{2}\right)=\left(\alpha_{2} / \alpha_{1}\right)\) (C) \(L_{1}^{2} \alpha_{1}=L_{2}^{2} \alpha_{2}\) (D) \(\alpha_{1}^{2} L_{1}=\alpha_{2}^{2} L_{2}\)

Short Answer

Expert verified
The answer is (B) \(L1/L2 = α2/α1\). This is the condition that ensures the difference between the lengths of the two rods remains constant regardless of the temperature change.

Step by step solution

01

Understanding the Concept

The length \( ΔL \) of an object under a temperature change \( ΔT \) is given by the formula \( ΔL = αL_0ΔT \), where \( α \) is the coefficient of linear expansion and \( L_0 \) is the initial length of the rod. As per the problem, the change in length of both rods is the same.
02

Formulate the Equations

Apply the formula for the change in length due to temperature for both rods. We have \( ΔL1 = α1L1ΔT \) and \( ΔL2 = α2L2ΔT \). As it's specified in the problem that the change in lengths stays the same across temperatures, we can equate these two expressions. This leads to \( α1L1ΔT = α2L2ΔT \).
03

Simplify the Equation

Solving the equation \( α1L1ΔT = α2L2ΔT \), we can cancel the \( ΔT \) from both sides since it's common to both. It leads us to \( α1L1 = α2L2 \). If we rearrange this to get \( L1/L2 \), it gives us \( L1/L2 = α2/α1 \).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The root mean square velocity of the gas molecules is \(300 \mathrm{~m} / \mathrm{s}\). What will be the root mean square speed of the molecules if the atomic weight is double and absolute temperature is halved? (A) \(300 \mathrm{~m} / \mathrm{s}\) (B) \(150 \mathrm{~m} / \mathrm{s}\) (C) \(600 \mathrm{~m} / \mathrm{s}\) (D) \(75 \mathrm{~m} / \mathrm{s}\)

A wire suspended vertically from one of its ends is stretched by attaching a weight of \(200 \mathrm{~N}\) to the lower end. The weight stretches the wire by \(1 \mathrm{~mm}\). The elastic energy stored in the wire is (A) \(0.2 \mathrm{~J}\) (B) \(10 \mathrm{~J}\) (C) \(20 \mathrm{~J}\) (D) \(0.1 \mathrm{~J}\)

An aluminium sphere of \(20 \mathrm{~cm}\) diameter is heated from \(0^{\circ} \mathrm{C}\) to \(100^{\circ} \mathrm{C}\). Its volume changes by (given that the coefficient of linear expansion for aluminium \(\left.\alpha_{A l}=23 \times 10^{-6} /{ }^{\circ} \mathrm{C}\right)\) (A) \(28.9 \mathrm{cc}\) (B) \(2.89 \mathrm{cc}\) (C) \(9.28 \mathrm{cc}\) (D) \(49.8 \mathrm{cc}\)

As the temperature is increased, the period of pendulum, (A) Increases as its effective length increases even though its centre of mass still remains at the centre of the bob. (B) Decreases as its effective length increases even through its centre of mass still remains at the centre of the bob. (C) Increases as its effective length increases due to shifting to centre of mass below the centre of the bob. (D) Decreases as its effective length remains same but the centre of mass shifts above the centre of the bob.

The radius of a metal sphere at room temperature \(T\) is \(R\) and the coefficient of linear expansion of the metal is \(\alpha .\) The sphere heated a little by a temperature \(\Delta T\) so that its new temperature is \(T+\Delta T\). The increase in the volume of the sphere is approximately. (A) \(2 \pi R \alpha \Delta T\) (B) \(\pi R^{2} \alpha \Delta T\) (C) \(4 \pi R^{3} \alpha \Delta T / 3\) (D) \(4 \pi R^{3} \alpha \Delta T\)

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.