Top 350+ Solved Electromagnetics MCQ Questions Answer
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. 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. 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
Q. A positive and a negative charge are initially 50 mm apart. When they are moved closetogether so that they are now only 10 mm apart, the force between them will be
a. 5 times smaller than before
b. 5 times greater than before
c. 10 times greater than before
d. 25 times larger than before
Q. Which is the most superior dielectric out of the following ?
a. air
b. glass
c. bakelite
d. paper
Q. When a dielectric is placed in an electric field the field strength
a. decreases
b. increases
c. reduces to zero
d. remain unchanged
Q. To prevent the generation of static charges on rubber or flat leather
a. surface is moistened
b. conductive dressing is done
c. oil compound dressing is done
d. talcum powder is sprayed on the surface