A coil of area 500 cm2 having 1000 turns is placed such that the plane of the coil is perpendicular to a magnetic field of magnitude 4 × 10-5 weber/m2. If it is rotated by 180° about an axis passing through one of its diameter in 0.1 sec, find the average induced emf.

  • Option 1)

    zero

  • Option 2)

    30 mV

  • Option 3)

      40 mV

  • Option 4)

     20 mV

 

Answers (1)

 

Rate of change of magnetic Flux -

\varepsilon = \frac{-d\phi }{dt}
 

- wherein

d\phi\rightarrow \phi _{2}-\phi _{1}

\phi _{2}-\phi _{1}- change in flux

 

 Average induced EMF = |\frac{\Delta \phi }{\Delta t}|

\phi_2 =-\phi_1 (since it is turned by 180^{\circ}

E_{av}=\frac{|\phi _2- \phi _1}{\Delta t}=\frac{2 \phi_1}{\Delta t} =\frac{2\times NBA}{\Delta t}

=\frac{2\times 1000\times 4\times 10^{-5}\times 5\times 10^{-2}}{0.1} =40mV

 


Option 1)

zero

Incorrect

Option 2)

30 mV

Incorrect

Option 3)

  40 mV

Correct

Option 4)

 20 mV

Incorrect

Preparation Products

Knockout BITSAT 2021

It is an exhaustive preparation module made exclusively for cracking BITSAT..

₹ 4999/- ₹ 2999/-
Buy Now
Knockout BITSAT-JEE Main 2021

An exhaustive E-learning program for the complete preparation of JEE Main and Bitsat.

₹ 27999/- ₹ 16999/-
Buy Now
Exams
Articles
Questions