Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 20: Q62P (page 861)

A metal rod of length L slides horizontally at constant speed v on frictionless insulating rails through a region of uniform upward magnetic field of magnitude B (Figure 20.124).

On a diagram, show the polarization of the rod and the direction of the Coulomb electric field inside the rod. Explain briefly. What is the magnitude of the Coulomb electric field inside the rod? What is the potential difference across the rod? What is the emf across the rod? What are the magnitude and direction of the force you have to apply to keep the rod moving at a constant speed v?

Short Answer

Expert verified

(i) E=BV

(ii)The diagram is drawn below.

(iii)e=BLV

(iv)F=B2L2VR

Step by step solution

01

Given Data

Length=LSpeed=vMagnetic Field=B

02

Concept

The phenomenon occurred because of the wave nature of the radiation of the electromagnetic force is known as polarization.

03

Step 3(i): Find the magnitude of the Coulomb electric field inside the rod 

At equilibrium of electron inside the rod,

eE=eVBE=BV

Hence, the magnitude of the Coulomb electric field inside the rod E=BV

04

Step 4(ii): Find the potential difference across the rod

Since, electron experiences force in upward direction means “electric field” is in downward direction .Therefore from A to B as shown in figure.

05

Step 5(iii): Find the emf across the rod

emf, (electric field= potential difference)

e=ELe=BLV

Hence, the emf across the rod ise=BLV

06

Step 6(iv): Find the force

Force,

F=BIL=BeRL=BBLVRLF=B2L2VR

Hence the force isF=B2L2VR

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

In which direction will conventional current flow through the resistor in Figure 20.87? What will be the direction of the magnetic force on the moving bar?

A current carrying wire is oriented along the y axis. It passes through a region 0.6m in which there is a magnetic field of 4.5T in the+z direction. The wire experiences a force of 14.9N in the -x direction.

(a.) What is the magnitude of the conventional current in the wire?

A neutral metal rod of length 60 cm falls toward the Earth. The rod is horizontal and oriented east west. (1) Which end of the rod, east or west, has excess electrons? Explain using physics diagrams. (2) At a moment when the rod’s speed is 4m/s , approximately how many excess electrons are at the negative end of the rod?

A long solenoid with diameter 4 cm is in a vacuum, and a lithium nucleus ( 4 neutrons and 3 protons ) is in a clockwise circular orbit inside the solenoid ( Figure 20.102 ). It takes \({\bf{50ns}}\,\left( {{\bf{50 \times 1}}{{\bf{0}}^{{\bf{ - 9}}}}{\bf{s}}} \right)\) for the lithium nucleus to complete one orbit.

  1. Does the current in the solenoid run clockwise or counter clockwise ? Explain including physics diagrams.

We will consider the possibility that a free electron acted on by an electric field could gain enough energy to ionize an air molecule in a collision. (a) Consider an electron that starts from rest in a region where there is an electric field (due to some charged objects nearby) whose magnitude is nearly constant. If the electron travels a distance dand the magnitude of the electric field isE,what isthe potential difference through which the electron travels? (Pay attention to signs: Is the electron traveling with the electric field or opposite to the electric field?) (b) What is the change in potential energy of the system in this process? (c) What is the change in the kinetic energy of the electron in this process? (d) We found the mean free path of an electron in air to be about 5×10-7 m, and in the previous question you calculated the energy required to knock an electron out of an atom. What is the magnitude of the electric field that would be required in order for an electron to gain sufficient kinetic energy to ionize a nitrogen molecule? (e) The electric field required to cause a spark in air is observed to be about 3×106 V/mat STP. What is the ratio of the magnitude of the field you calculated in the previous part to the observed value at STP? (f) What is it reasonable to conclude about this model of how air becomes ionized? (1) Since we used accurate numbers, this is a huge discrepancy, and the model is wrong. (2) Considering the approximations we made, this is pretty good agreement, and the model may be correct.
See all solutions

Recommended explanations on Physics Textbooks

Space Physics

Read Explanation

Electric Charge Field and Potential

Read Explanation

Modern Physics

Read Explanation

Wave Optics

Read Explanation

Kinematics Physics

Read Explanation

Thermodynamics

Read Explanation
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.

Sign-up for free