(a) Derive the expression for the torque acting on a current-carrying loop placed in a magnetic field.
(b) Explain the significance of a radial magnetic field when a current-carrying coil is kept in it.

Answers (1)

Let us consider a loop ABCD in a uniform magnetic field of strength B. and Let the current through the loop be I.

Consider force F_{1} on arm AB and force F_{2} on arm CD.

F_{1}=F_{2}=IbB

The net torque is given by -

\tau = I\: \frac{a}{2}\: b\: B\: +I\: \frac{a}{2}\: b\: B\:

\tau = IAB

Where A is the area of the loop

Now,

The magnetic moment of the loop.

\vec{m}=I\vec{A}

Therefore

\tau = mB

This is the expression for the torque acting on a current-carrying loop placed in a magnetic field.

(b) In a radial magnetic field, two sides of the rectangular coil remain perpendicular and other two ides remain parallel to magnetic field lines in all position of the coil.

Most Viewed Questions

Related Chapters

Preparation Products

Knockout CUET (Physics, Chemistry and Mathematics)

Complete Study Material based on Class 12th Syllabus, 10000+ Question Bank, Unlimited Chapter-Wise and Subject-Wise Mock Tests, Study Improvement Plan.

₹ 7999/- ₹ 4999/-
Buy Now
Knockout CUET (Physics, Chemistry and Biology)

Complete Study Material based on Class 12th Syllabus, 10000+ Question Bank, Unlimited Chapter-Wise and Subject-Wise Mock Tests, Study Improvement Plan.

₹ 7999/- ₹ 4999/-
Buy Now
Knockout JEE Main (Six Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 9999/- ₹ 8499/-
Buy Now
Knockout JEE Main (Nine Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 13999/- ₹ 12499/-
Buy Now
Knockout NEET (Six Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 9999/- ₹ 8499/-
Buy Now
Boost your Preparation for JEE Main with our Foundation Course
 
Exams
Articles
Questions