The alternating current has frequency of 106 Hz in such a way that time period for completion of cycle is_______________?
A. 1Hzs
B. 1.5Hzs
C. 106sec
D. 1sec
Self inductance of a coil depends upon________________?
Self inductance of a coil depends upon________________?
A. current flowing
B. number of turns per unit length
C. voltage produce
D. all
Energy stored in a magnetic field is given by______________?
Energy stored in a magnetic field is given by______________?
A. LI2
B. L2I/2
C. LI2/2
D. IL2
For electroplating we use_________________?
For electroplating we use_________________?
A. A D.C source
B. an A.C source
C. any source
D. all of the above
The only difference between construction of D.C generator and A.C generator is that of_______________?
The only difference between construction of D.C generator and A.C generator is that of_______________?
A. carbon brushes
B. coil
C. commutator
D. magnetic field
If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by_____________?
If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by_____________?
A. Vs/Vp = Np/Ns
B. Vs/Vp = Ns/Np
C. Vp/Vs = Ns/Np
D. Vp/Vs = Np/Ns
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 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. 0 volt
B. 3.125 volt
C. 31.25 volt
D. 0.03125 volt
The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is because the soft iron core_______________?
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. 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
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____________?
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. 150msec-1
B. 384msec-1
C. 38.4msec-1
D. 200msec-1
Non inductive resistances are used in decreasing______________?
Non inductive resistances are used in decreasing______________?
A. Mutual inductance
B. Self inductance
C. Magnetic fields
D. Heating effect