Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

(a) How large a current would a very long, straight wire has to carry so that the magnetic field 2 cm from the wire is equal to (comparable to the earth’s northward-pointing magnetic field)? (b) If the wire is horizontal with the current running from east to west, at what locations would the magnetic field of the wire point in the same direction as the horizontal component of the earth’s magnetic field? (c) Repeat part (b) except the wire is vertical with the current going upward.

Short Answer

Expert verified

a) l = 10A

b) At all points directly above the wire the field of the wire would point northward.

c) At all points directly east of the wire, its field would point northward.

Step by step solution

01

The formula to calculate the current

The magnetic field due to a very long wire is given byB=μ0I2πr .

The current can be found byI=2πrBμ0 .

02

Calculate the current

Given that r = 2 cm andB=10-4T .

I=2πrBμ0I=2π×0.02×1044π×107I=10A

03

Find the locations of magnetic field

We know that earth’s horizontal field points northwards. Therefore, at all points directly above the wire the field of the wire would point northward as shown in the figure

Now, the wire is vertical with the current going upward, at all points directly east of the wire, its field would point northward as shown in the figure

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 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

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.

Sign-up for free