Question

A 250 turn rectangular coil of length 2.1 cm and width 1.25 cm carries a current of 85 microampere and subject to b=0.85t. work done for rotating coil by 180degree against the torque is

Answer 1

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Answer 2

Answer:

The work done  for rotating coil by 180 degree against the torque is $9.5\ \mu J$

Explanation:

Given that,

Number of turns N= 250

length l= 2.1 cm

Width d= 1.25 cm

Current I= 85 micro ampere

Magnetic field B=0.85 T

The work done for rotating

$W=MB(cos\theta_{1}-cos\theta_{2})$

Whet it rotated by the angle 180°

$W=2 MB$

$W==2(NIA)B$

$W= 2\times250\times85\times10^{-6}[\times2.1\times1.25\times10^{-4}]\times85\times10^{-2}$

$W=0.0000095 J$

$W=9.5\ \mu J$

Hence, The work done  for rotating coil by 180 degree against the torque is $9.5\ \mu J$