Top 80+ Solved Magnetism and Electromagnetism MCQ Questions Answer
Q. The commonly used material for shielding or screening magnetism is
a. copper
b. aluminium
c. soft iron
d. brass
Q. If a copper disc is rotated rapidly below a freely suspended magnetic needle, themagnetic 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
Q. A permanent magnet
a. attracts some substances and repels others
b. attracts all paramagnetic substan¬ces and repels others
c. attracts only ferromagnetic sub¬stances
d. attracts ferromagnetic substances and repels all others
Q. The retentivity (a property) of material is useful for the construction of
a. permanent magnets
b. transformers
c. non-magnetic substances
d. electromagnets
Q. The relative permeability of materials is not constant.
a. diamagnetic
b. paramagnetic
c. ferromagnetic
d. insulating
Q. The materials are a bit inferior conductors of magnetic flux than air.
a. ferromagnetic
b. paramagnetic
c. diamagnetic
d. dielectric
Q. Hysteresis loop in case of magnetically hard materials is more in shape as compared tomagnetically soft materials.
a. circular
b. triangular
c. rectangular
d. none of the above
Q. A keeper is used to
a. change the direction of magnetic lines
b. amplify flux
c. restore lost flux
d. provide a closed path for flux
Q. Magnetic moment is a
a. pole strength
b. universal constant
c. scalar quantity
d. vector quantity
Q. 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) b >th in the same way
d. none of the above
Q. The uniform magnetic field is
a. the field of a set of parallel conductors
b. the field of a single conductor
c. the field in which all lines of mag¬netic flux are parallel and equidis¬tant
d. none of the above
Q. The magneto-motive force is
a. the voltage across the two ends of exciting coil
b. the flow of an electric current
c. the sum of all currents embraced by one line of magnetic field
d. the passage of magnetic field through an exciting coil
Q. What will be the magnetic potential difference across the air gap of 2 cm length inmagnetic field of 200 AT/m ?
a. 2 AT
b. 4 AT
c. 6 AT
d. 10 AT