Question

6. A long, straight wire has a 10.0-

Answer 1

please note : here i am taking current i=10A and I2=2A because i cant read the units properly. for me its showing someting like this i=10.0@? A

Required theory

• The magnetic field produced by an infinite wire carrying a current i at a point P which is at s distance away from the wire is given by

The direction of this magnetic field is given by the right hand thumb rule .If thumb points in the direction of current then the curling fingures at that point will give the direction of magnetic field.

• When a current carrying element of length l and current i is placed in a magnetic field B ,it will experience a magnetic force given by direction of l is the direction of current.The direction of this force is given by the right hand rule.

Consider the figure below

The direction of magnetic filed on the right hand side of the wire carrying current I1 is in to the plane(By right hand rule).

The current I2 is clock wise in the loop thus the force experianced in the DA of the loop is towards the wire and in BC is away from the wire (By right hand rule).On AB the force is in upward direction and on DC its in downward direction.But the net force in the vertical direction is zero because there exists identical elemets in AB and DC for which the magnitude of force is same bt the direction is oppositeto each other.

a)Force acting on DA

magnetic field due to wire at a distance d= 0.5m equals

in to the plane.

the force experienced by DA=

towards the wire.

(since B and i are perpendicular  )

Force acting on BC

magnetic field due to wire at a distance d= 0.5+0.75 =1.25 m equals

in to the plane.

the force experienced by BC=

away from the wire.

(since B and i are perpendicular  )

net force between the wire and the loop

towards the wire.

b) there is no net torque on the loop.As there is no force to produce a rotation of the loop.