Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo
Physics

Problems

PhysicsProblems

Problems

20.1 Magnetic Fields, Field Lines, and Force

18.

A straight wire segment carries 0.25 A. What length would it need to be to exert a 4.0-mN force on a magnet that produces a uniform magnetic field of 0.015 T that is perpendicular to the wire?

  1. 0.55 m
  2. 1.1 m
  3. 2.2 m
  4. 4.4 m

20.3 Electromagnetic Induction

19.

What is the current in a wire loop of resistance 10 Ω through which the magnetic flux changes from zero to 10 Wb in 1.0 s?

  1. –100 A
  2. –2.0 A
  3. –1.0 A
  4. +1.0 A
20.

An emf is induced by rotating a 1,000 turn, 20.0 cm diameter coil in Earth’s 5.00 × 10–5 T magnetic field. What average emf is induced, given the plane of the coil is originally perpendicular to Earth’s field and is rotated to be parallel to the field in 10.0 ms?

  1. –1.6 × 10-4 V
  2. +1.6 × 10-4 V
  3. +1.6 × 10-1 V
  4. –1.6 × 10-1 V
Order a print copy

As an Amazon Associate we earn from qualifying purchases.

Citation/Attribution

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute Texas Education Agency (TEA). The original material is available at: https://www.texasgateway.org/book/tea-physics . Changes were made to the original material, including updates to art, structure, and other content updates.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at https://openstax.org/books/physics/pages/1-introduction
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at https://openstax.org/books/physics/pages/1-introduction
Citation information

© Jan 19, 2024 Texas Education Agency (TEA). The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.