A. is constant and has same value in energy part of the magnetic field
B. increases continuously from initial value to final value
C. decreases continuously from initial value to final value
D. first increases and then decreases till it becomes zero
Related Mcqs:
- The electromagnet has 50 turns and a current of 1A flows through the coil. If the length of the magnet circuit is 200 mm, what is the magnetic field strength ?
A. 2500 AT/m
B. 250 AT/m
C. 25 AT/m
D. 2.5 AT/m - A rectangular magnet of magnetic moment M is cut into two piece of same length, the magnetic moment of each piece will be______________?
A. M
B. M/2
C. 2 M
D. M/4 - A square cross-sectional magnet has a pole strength of 1 x 10 Wb and cross sectional area of 20 mm x 20 mm. What is the strength at a distance of 100 mm from the unit pole in air ?
A. 63.38 N/Wb
B. 633.8 N/Wb
C. 6338 N/Wb
D. 63380 N/Wb - How does the magnetic compass needle behave in a magnetic field ?
A. It assures a position right angle to magnetic field
B. It starts rotating
C. It assures a position which follows a line of magnetic flux
D. None of the above - What will be the magnetic potential difference across the air gap of 2 cm length in magnetic field of 200 AT/m ?
A. 2 AT
B. 4 AT
C. 6 AT
D. 10 AT - The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields______________?
A. meter is surrounded by strong magnetic fields
B. a soft iron shielding is used
C. a plastic shielding is provided
D. a shielding of anon-magnetic material is used - If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity?
A. less than that of disc but in opposite direction
B. equal to that of disc and in the same direction
C. equal to that of disc and in the opposite direction
D. less than that of disc and in the same direction - The change of cross-sectional area of conductor in magnetic field will affect______________?
A. reluctance of conductor
B. resistance of conductor
C. A. and B. both in the same way
D. none of the above - A 300 mm long conductor is carrying a current of 10 A and is situated at right angles to a magnetic field having a flux density of 0.8 T ; the force on the conductor will be____________?
A. 240 N
B. 24 N
C. 2.4 N
D. 0.24 N - A material which is slightly repelled by a magnetic field is known as_____________?
A. ferromagnetic material
B. diamagnetic material
C. paramagnetic material
D. conducting material
