GravitationHard

Question

A long straight wire of radius a carries a steady current i. the current is uniformly distributed across its cross section .The ratio of the magnetic field at a/2 and 2a is

Options

A.1/2
B.1/4
C.4
D.1

Solution

         
Here, current is uniformly distributed across the cros-section of the wire, therforecurrent enclosed in the amperean path
formed at a distance r1
× 1, where I total current
∴ Magnetic field at
P1(B1) =

Now, magnatic field at point P2,
(B2) =
∴     Required Ratio =
     

Create a free account to view solution

View Solution Free
Topic: Gravitation·Practice all Gravitation questions

More Gravitation Questions

Find the distance between centre of gravity and centre of mass of a two particle system attached to the ends of a light ...A satellite is revolving round the earth with orbital speed v0. If it stops suddenly, the speed with which it will strik...A planet is revolving around the Sun in an elliptical orbit. Its closest distance from the Sun is rmin. The farthest dis...Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1m, 2m, 4m, 8m, ...., respectively, from...Which of the following most closely depicts the correct variation of the gravitation potential V(r) dueto a large planet...