Home
Class 12
PHYSICS
A wire of length l carries a steady curr...

A wire of length l carries a steady current. It is bent first to form a circular plane loop of one turn. The magnetic field at the centre of the loop is B. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same is

A

B

B

2B

C

3B

D

4B

Text Solution

Verified by Experts

The correct Answer is:
D
`B_1=B=(mu_0 n_1 I)/(2r_1)=B`
When same length is bent into 2 turns radius of coil is halved
`B_2=(mu_0 n_2 I)/(2 r_2)=4(mu_0 I)/(2 r) = 4B`
`(B_2)/(B_1)=(4B)/(B)=(4)/(1)`
`B_2=4B_1=4B`.
Promotional Banner

Topper's Solved these Questions

  • MAGNETIC EFFECT OF ELECTRIC CURRENT

    NIKITA PUBLICATION|Exercise MCQs (Sensitivity and accuracy of M.C.G.)|1 Videos

  • KINETIC THEORY OF GASES & RADIATION

    NIKITA PUBLICATION|Exercise MCQs (Question Given in MHT-CET)|79 Videos

  • MAGNETISM

    NIKITA PUBLICATION|Exercise MCQs|249 Videos

Similar Questions

Explore conceptually related problems

A length lof wire carries a steady current i. It is bent first to form a circular plane coil of one turn . The same length is now bent more sharply to give three loops of smaller radius . The magnetic field at the centre caused by the same current is

A square loop of side a carris a current I . The magnetic field at the centre of the loop is

A length of wire carries a steady current I. It is bent first to form a circular plane coil of one turn. The same length is now bent more sharply to give double loop of smaller radius. If the same current I is passed, the ratio of the magnitude of magnetic field at the centre with its first value is:

On meter length of wires carriers a constant current. The wire is bent to from a circular loop. The magnetic field at the centre of this loop is B . The same is now bent to form a circular loop of smaller radius to have four turns in the loop. The magnetic field at the centre of this loop B . The same is now bent to form a circular loop of smaller radius of have four turns in the loop. The magnetic field at the centre of this new loop is

A length of wire carries a steady current. It is first bent to form a circular coil of one turn. The same length is now bent more sharply to give a loop of two turns of smaller radius. The magentic field at the centre caused by the same current now will be

A square loop of edge 'a' carries a current l. The magnetic field at the centre of loop is