Home
Class 12
PHYSICS
Circular loop of a wire and a long strai...

Circular loop of a wire and a long straight wire carry current `I_(c )` and `I_(e )`respectively as shown in figure. Assuming that these are placed in the same plane. The magnetic field will be zero at the centre of the loop when the separation `H` is:

A

`(l_(e)R)/(l_(e)pi)`

B

`(l_(e)R)/(l_(e)pi)`

C

`(pil_(e))/(l_(e)R)`

D

`(l_(e)pi)/(l_(e)R)`

Text Solution

Verified by Experts

The correct Answer is:
A
Magnetic field du to a circular loop at the centre of the loop is `B_(1)'=(mu_(0))/(4pi) (2pil_(c))/(R)`
Magnetic field due to a stright line at the centre of the loop is `B_(2)=(mu_(0)2l_(e))/(4piH)`
Both these field act in opposite directio hence total magnetic field at the centre of the loop is
`B=B_(1)-B_(2)=(mu_(2)2pil_(e))/(4pir) -(mu_(0)2l_(e))/(4piH)`
B=0 given
`:. (mu2pil_(e))/(4piR)=(mu_(0)2l_(e))/(4piH) or, H-(l_(e)R)/(pil_(e))`
Promotional Banner

Similar Questions

Explore conceptually related problems

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

A circular loop of radius r carries a current i. where should a long , straight wire carrying a current 4i be placed in the plane of the circle so that the magnetic field at the centre becomes zero?

A circular loop of radius r carries a current i. How should a long, straight wire carrying a current 4i be placed in the plane of the circle so that the magnetic field at the center becomes zero?

A rectangular loop of metallic wire is of length a and breadth b and carries a current i. The magnetic field at the centre of the loop is

The wire loop shown in figure carries a current as shown. The magnetic field at the centre O is ,

B_0 is the magnetic field at point P fir s given straight wire as shown in figure. If this wire is bent into a circular loop,then magnetic field at the center of the loop is

The location of three long wires carrying same current I are x=-a , x=0 and x=+ a respectively as shown in figure. The magnetic field at point ( 0 , 0 , a ) is

A triangular loop (ABC) having current i_(2) and an infinite wire having current i_(1) are placed in the same plane.Find the magnetic force of interaction between the infinite wire and the loop ABC .

B_0 is the magnetic field at point P for a given straight wire as shown in figure. If this wirre is bent into a circular loop, then magnetic field at the centre of loop is

A non - popular loop of conducting wire carrying a current I is placed as shown in the figure . Each of the straighrt sections of the loop is of the length 2a . The magnetic field due to this loop at the point P(a, 0 ,a) points in the direction