Tag: mutual inductance

Questions Related to mutual inductance

Two coils A and B have mutual inductance $2\times { 10 }^{ -2 }$ henry. If the current in the primary is $i=5\sin { \left( 10\pi t \right)  } $ then the maximum value of e.m.f.induced in coil B is 

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. $\pi \quad volt$

  2. $\pi /2volt$

  3. $\pi /3volt$

  4. $\pi /4volt$

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Correct Option: A

When the primary current in the spark-coil of a car changes from $4A$ to zero in $10\mu s$, an emf of $40000$V is induced in the secondary. The mutual inductance between the primary and the secondary winding of the spark-coil will be-

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. 1 H

  2. 0.1 H

  3. 10 H

  4. zero

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Correct Option: A

Two coils A and B have mutual inductance $2\times { 10 }^{ -2 }$ henry. If the current in the primary is $i=5\sin { \left( 10\pi t \right)  } $ then the maximum value of e.m.f. induced in coil B is

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. $\pi \quad volt$

  2. $\pi /2volt$

  3. $\pi /3volt$

  4. $\pi /4volt$

Show answer
Correct Option: A

The electric field of an electromagnetic wave is given by, $E=(50N^{-1})\, \sin { \omega  } (t-x/c)$. Find the energy contained in a cylinder of cross section $10cm^2$ and length $50 cm$ along the x-axis.

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. $5.5\times 10^{-12}J$

  2. $4.5\times 10^{-12}J$

  3. $5\times 10^{-13}J$

  4. $3.5\times 10^{-10}J$

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Correct Option: A

An electron having kinetic energy T is moving in a circular orbit of radius R perpendicular to a uniform magnetic induction $\vec { \mathrm { B } }$  If kinetic energy is doubled and magnetic induction tripled, the radius will

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. $\frac { 3 R } { 2 }$

  2. $ \frac{{\sqrt 2 }}{3}R$

  3. $\sqrt { \frac { 2 } { 9 } } R$

  4. $\sqrt { \frac { 4 } { 3 } } R$

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Correct Option: B
Explanation:

We know$,$

$R = \frac{{\sqrt {2mk} }}{{qB}}$
$R' = \frac{{\sqrt {2m2k} }}{{q\left( {3B} \right)}}$
$ = \frac{{\sqrt 2 }}{3}\frac{{\sqrt {2mk} }}{{qB}}$
$ = \frac{{\sqrt 2 }}{3}R$
Hence,
option $(B)$ is correct answer.

An average induced emf of 0.4 V appears in a coil when the current in it is changed from 10 A in one direction to 10 A in opposite direction in 0.5 sec. self-inductance of the coil is.

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. 0.008H

  2. 50 H

  3. 75 H

  4. 100 H

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Correct Option: A

At any instant t currenetI thorugh a coil of sself inductance 2mH is given.The induced e.m.f will be zero at time    

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. 1 sec

  2. 2 sec

  3. 3 sec

  4. 4 sec

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Correct Option: B

When a current of 5 A flows in the primary coil then the flux linked with the secondary coil is 200 weber. The value of coefficient of mutual induction will be

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. 1000 H

  2. 40 H

  3. 195 H

  4. 205 H

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Correct Option: B
Explanation:

Coefficient of mutual induction will be the ratio of the flux linked with the secondary coil and the current primary coil.


$ M = \dfrac{200}{5} = 40 H $ 

A cylindrical magnet is kept along the axis of a circular coil. On rotating the magnet about its axis. the coil will have induced in it

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. No current

  2. A current

  3. Only an e.m.f.

  4. Both an e.m.f. and a current

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Correct Option: A

A coil of insulating wire is connected to battery. If it is moved towards a galvanometer then its point gets deflected because

mutual inductance electromagnetic induction electromagnetic induction and alternating currents physics

  1. the coil behaves like a magnet

  2. induced current is produced in the coil

  3. the number of turns in the galvanometer coil remains constant

  4. none of the above

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Correct Option: B
Explanation:

Upon connecting to the battery , a current starts to flow in the insulated wire. This current induces a current in the galvanometer coil  due to mutual  inductance because of the flux linkages. This induced current causes a deflection in the galvanometer .