Question

A loop of flexible conducting wire lies in a magnetic field of 4.0 T with its plane perpendicular to the field. The length of the wire is 1 m. When a current of 2.2 A is passed through the loop, it opens into a circle, then the tension developed in the wire is ____________.

पर्याय

• 0.5 .N

• 0.25 N

• 1.4 N

• 0.4 N

Answer 1

A loop of flexible conducting wire lies in a magnetic field of 4.0 T with its plane perpendicular to the field. The length of the wire is 1 m. When a current of 2.2 A is passed through the loop, it opens into a circle, then the tension developed in the wire is 1.4 N.

Explanation:

As the coil is perpendicular to magnetic field

`vec "B" = 2 "T",`

`theta = 90°`

The loop formed is circular,

`therefore l = 2  pi"r"`

As the force acting on the loop will be along radius,

`"r" = l/(2pi)`

∴ Tension developed is

`"T" = "F" = "B"  "I"  "r  sin"  theta = "B"  "I"  "r"`

`= (4 xx 2.2 xx l)/(2pi)`

` = 4.4/pi`

` = 1.4  "N"`