Top 250+ Solved Electromagnetic Theory MCQ Questions Answer
Q. Paper condenser is
a. always polarised
b. usually of fixed value
c. electrolytic condenser
d. a variable condenser
Q. Mica capacitors are characterised by all of thte following except
a. stable operation
b. accurate value
c. low leakage reactance
d. low losses
Q. A potential of 400 V is applied to a capacitor, the plates of which are 4 mm apart. Thestrength of electric field is
a. 100 kV/m
b. 10 kV/m
c. 5 kV/m
d. 2 kV/m
Q. For a good 0.05 uF capacitor ohmmeter reading should
a. show low resistance momentarily and back off to a very high resis¬tance
b. show high resistance momentarily and then a very low resistance
c. go quickly to 50 ohm approximately and remain there
d. not move at all
Q. The ohmmeter reading for a short circuited capacitor is
a. infinity
b. few kilo ohms
c. few megaahms
d. zero
Q. Which of the following statements is correct ?
a. Mica capacitors are available in capacitance values of 5 to 20 \iF
b. Air capapitors have a black band to indicate the outside foil
c. Electrolytic capacitors must be connected in correct polarity
d. Ceramic capacitors must be con¬nected in correct polarity
Q. Which of the following capacitors preferred for high frequency circuits ?
a. Air capacitor
b. Electrolytic capacitor
c. Mica capacitor
d. none of the above
Q. An electrolytic capacitor is generally made to provide
a. low capacitance
b. fixed capacitance
c. variable capacitance
d. large value of capacitance
Q. In order to remove static electricity from machinery
a. construct insulated cabins
b. insulate the machinery
c. ground the framework
d. humidify the surroundings
Q. If a third equal and similar charge is placed between two equal and similar charges,then this third charge will
a. move out of the field of influence of the two charges
b. remain in stable equilibrium
c. not be in equilibrium
d. be in unstable equilibrium
Q. A region around a stationary electric charge has
a. an electric field
b. a magnetic field
c. both (a) and (b)
d. none of the above
Q. The minimum value of potential gradient in a cable occurs in
a. insulation
b. conductor
c. outer sheath
d. uniformly all over
Q. Dielectric strength of medium
a. increases with rise in temperature
b. increases with moisture content
c. is same for all insulating materials
d. none of the above
Q. Acharge which when placed in vacuum from an equal and similar charge repels with aforce of 9 x 10 N, is known as
a. milli-coulomb
b. micro-coulomb
c. pico-coulomb
d. coulomb