Two parallel wires carrying currents in the opposite directions:
A. repel each other
B. attract each other
C. have no effect upon each other
D. they cancel out their individual magnetic fields
If a current carrying solenoid is suspended freely it will:
A. be rotating
B. come to rest in N-S direction
C. vibrating like galvanometer needle
D. comes to rest after rotation
Which one of the following is not an electromechanical instrument:
A. galvanometer
B. voltmeter
C. ammeter
D. AC transformer and DC generator
When the coil of the galvanometer is in equilibrium then the deflecting couple is:
A. zero
B. equal to the restoring couple
C. greater than the restoring couple
D. smaller than the restoring couple
The sensitivity of a galvanometer is given by:
A. C/BAN
B. CAN/B
C. BAN/C
D. ABC/N
The magnetic field strength of solenoid is:
A. B = μNI
B. B = μN/I
C. B = μnI
D. Both B and C
Electromagnetic waves travel in free space with the speed of:
A. λ-rays
B. Positive rays
C. Cathode rays
D. More than sound waves
Heating a magnet will:
A. weaken it
B. strengthen it
C. reverse its polarity
D. demagnetize it completely
Galvanometer is a very sensitive device with:
A. very low damping
B. very high damping
C. no damping at all
D. radial field disintegration
Electromagnetic waves emitted from antenna are:
A. Stationary
B. Longitudinal
C. Transverse
D. All the above
