A. Maximum
B. Zero
C. Intermediate values
D. No back emf
0
Lagging of changes in the magnetization of a substance behind changes in the magnetic field as the magnetic field is varied is known as magnetic_____________?
0
For long distance transmission the transformer used is_____________?
A. Retaintivity
B. Permeability
C. Flux
D. Hysteresis
0
Which one of the following devices does not function like an electric motor ?
A. Step down
B. Input voltage and output voltage remain same
C. Step up
D. Amplifier is used
0
Non inductive resistances are used in decreasing______________?
A. Galvanometer
B. Ammeter
C. Voltmeter
D. Transformer
0
An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are perpendicular to the vertical component of the earths magnetic field (B = 4×10-5T). At maximum speed an emf of 96mV is induced across the wing tips. The maximum speed of the aeroplane is____________?
A. Mutual inductance
B. Self inductance
C. Magnetic fields
D. Heating effect
0
The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is because the soft iron core_______________?
A. 150msec-1
B. 384msec-1
C. 38.4msec-1
D. 200msec-1
0
A metal rod of 25 cm length is moving at a speed of 0.5/sec in direction perpendicular to 0.25T magnetic field. Emf produced in the rod is_____________?
A. Decreases the resistance of the solenoid
B. Reduces the effect of eddy current
C. Improves the flux linkage between the turns of the coil
D. Increases the mutual inductance between the solenoid and the core
0
If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by_____________?
A. 0 volt
B. 3.125 volt
C. 31.25 volt
D. 0.03125 volt
0
The only difference between construction of D.C generator and A.C generator is that of_______________?
A. Vs/Vp = Np/Ns
B. Vs/Vp = Ns/Np
C. Vp/Vs = Ns/Np
D. Vp/Vs = Np/Ns
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