‘X’ set up in the drum exert a torque on the drum to stop the train. Identify X.
A. Eddy currents
B. Air pressure
C. Induction
D. Electromagnetic oscillations
Electromagnetic Induction
Electromagnetic Induction Mcqs
What is measured by the eddy currents induced in energy meters ?
A. Electric power
B. Electric energy
C. Electric potential
D. Electric induction
Two 300 uH coils in series without mutual coupling have a total inductance of _____.
A. 150 uH
B. 75 uH
C. 600 uH
D. 300 uH
Lenz’s law is a consequence of the law of conservation of _____.
A. Energy
B. Induced e.m.f.
C. Induced current
D. Charge
Which of the following is unit of inductance ?
A. Henry
B. Weber/metre
C. Ohm
D. Ampere turns
The direction of induced e.m.f. can be found by:
A. Fleming’s right hand rule
B. Kirchhoff s voltage law
C. Lenz’s law
D. Laplace’s law
An open coil has _____.
A. Infinite resistance and normal inductance
B. Zero resistance and high inductance
C. Infinite resistance and zero inductance
D. Zero resistance and inductance
Which of the following is not a unit of inductance ?
A. Coulomb/volt ampere
B. Volt second per ampere
C. Henry
D. All of the above
A crack in the magnetic path of an inductor will result in ______.
A. Zero inductance
B. Reduced inductance
C. Unchanged inductance
D. Increased inductance
The coefficient of coupling between two air core coils depends on _____.
A. Mutual inductance between two coils only
B. Mutual inductance and self inductance of two coils
C. Self-inductance of two coils only
D. None of the above