The property of coil by which a counter e.m.f. is induced in it when the current through the coil changes is known as__________?

A. Self-inductance
B. Mutual inductance
C. Series aiding inductance
D. Capacitance

The direction of induced e.m.f. can be found by_____________?

A. Laplace’s law
B. Lenz’s law
C. Fleming’s right hand rule
D. Kirchhoff s voltage law

An open coil has_____________?

A. Zero resistance and inductance
B. Infinite resistance and zero inductance
C. Infinite resistance and normal inductance
D. Zero resistance and high inductance

The inductance of a coil will increase under all the following conditions except______________?

A. When more length for the same number of turns is provided
B. When the number of turns of the coil increase
C. When more area for each turn is provided
D. When permeability of the core increases

As per Faraday’s laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it_______________?

A. Lies perpendicular to the magnetic flux
B. Lies in a magnetic field
C. Cuts magnetic flux
D. Moves parallel to the direction of the magnetic field

In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will_____________?

A. Increase
B. Decrease
C. Remain the same
D. Initially increase and then decrease

Both the number of turns and the core length of an inductive coil are doubled. Its self-inductance will be_____________?

A. Unaffected
B. Doubled
C. Halved
D. Quadrupled

Higher the self-inductance of a coil_____________?

A. Lesser its weber-turns
B. Lower the e.m.f. induced
C. Greater the flux produced by it
D. Longer the delay in establishing steady current through it

Which of the following circuit element stores energy in the electromagnetic field ?

A. Inductance
B. Condenser
C. Variable resistor
D. Resistance

Those magnetic materials are best suited for making armature and transformer cores which have ________ permeability and ________ hystersis loss

A. High, high
B. Low, high
C. High, low
D. Low, low