Home
Class 12
PHYSICS
By a change of current from 5 A to 10 A...

By a change of current from 5 A to 10 A in 0.1 s, the self induced emf is 10 V. The change in the energy of the magnetic field of a coil will be

A

`5J`

B

`6J`

C

`7.5J`

D

`9J`

Text Solution

Verified by Experts

The correct Answer is:
C
` |epsi|=L(DeltaI)/(Deltat)`
`L=(|epsi|)/(DeltaI)=(10xx0.1)/((10-5))=0.2H`
The magnetic field energies for currents `I_(1) and I_(2)` are `U_(1)=(1)/(2)LI_(1)^(2) and U_(2)=(1)/(2)LI_(2)^(2)`
Change I energy `= U_(2)-U_(1)`
`=(1)/(2)LI_(2)^(2)=-(1)/(2)LI_(2)^(2)=(L)/(2)(I_(2)^(2)-I_(1)^(2))`
`=(0.20)/(2)(10^(2)-5^(2))7.5J`
Promotional Banner

Topper's Solved these Questions

  • ELECTROMAGNETIC INDUCTION

    NCERT FINGERTIPS ENGLISH|Exercise EXEMPLAR PROBLEMS|3 Videos

  • ELECTROMAGNETIC INDUCTION

    NCERT FINGERTIPS ENGLISH|Exercise ASSERTION AND REASON|15 Videos

  • ELECTRIC CHARGES AND FIELDS

    NCERT FINGERTIPS ENGLISH|Exercise Assertion And Reason|15 Videos

  • ELECTROMAGNETIC WAVES

    NCERT FINGERTIPS ENGLISH|Exercise Assertion And Reason|15 Videos

Similar Questions

Explore conceptually related problems

In a circular conducting coil, when current increases from 2A to 18A in 0.05 sec., the induced e.m.f. is 20V . The self-inductance of the coil is

In a coil current falls from 5 A to 0 A in 0.2 s. If an average emf of 150 V is induced, then the self inductance of the coil is

When current in coil is uniformely reduced from 2A to 1A in 1 ms , the induced emf is 5V. The inductance of coil is :

If a current of 10 A changes in one second through a coil, and the induced emf is 20 V, then the self-inductance of the coil is

When the current changes from +2A to -2A in 0.05s , and emf of 8V is induced in a coil. The coefficient of self-induction of the coil is

When the current in a coil charges from 2A to 4A in 0.5 s, emf of 8 volt is induced in the coil. The coefficient of self induction of the coil is -

If the current in the primary circuit of a pair of coils changes from 5 amp to 1 amp in 0.02 sec, calculate (i) induced emf in the secondary coil if the mutual inductance between the two coils is 0.5H and (ii) the change of flux per turn in the secondary, if it has 200 turns.

When current in a coil changes from 5 A to 2 A in 0.1 s, average voltage of 50 V is produced. The self - inductance of the coil is :

When current in a coil changes from 25 A to 12 A in 0.1 s , average voltage of 50 V is produced .The self inductance of the coil is

The current decays from 5A to 2A in 0.01s in a coil. The emf induced in a coil nearby it is 30V. Calculate the mutual inductance of the coil.