204
85.5k

290+ Electromagnetic Field Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Electrical Engineering , Electronics and Communication Engineering .

251.

Which of the following material has least value of dielectric constant ?

A. Ceramics
B. Oil
C. Glass
D. Paper
Answer» B. Oil
252.

Which of the following capacitors will have the least value of breakdown voltage ?

A. Mica
B. Paper
C. Ceramic
D. Electrolytic
Answer» D. Electrolytic
253.

Dielectric constant for mica is nearly

A. 200
B. 100
C. 3 to 8
D. 1 to 2
Answer» C. 3 to 8
254.

The value of dielectric constant for vacuum is taken as

A. zero
B. 1
C. 4
D. 10
Answer» B. 1
255.

Which of the following capacitors is marked for polarity ?

A. Air
B. Paper
C. Mica
D. Electrolytic
Answer» D. Electrolytic
256.

Which of the following capacitors can be used for temperature compensation ?

A. Air capacitor
B. Ceramic capacitor
C. Paper capacitor
D. None of the above
Answer» B. Ceramic capacitor
257.

Which of the following statements is incorrect ?

A. The thinner the dielectric, the more the capacitance and the lower the voltage breakdown rating for a capacitor .
B. A six dot mica capacitor colour coded white, green, black, red and yellow has the capacitance value of 500 pF
C. Capacitors in series provide less capacitance but a higher voltage breakdown rating for the combina¬tion
D. A capacitor can store charge be¬cause it has a dielectric between two conductors
Answer» B. A six dot mica capacitor colour coded white, green, black, red and yellow has the capacitance value of 500 pF
258.

Paper capacitors usually have a tolerance of

A. ± 5%
B. ± 10%
C. ± 15%
D. ± 20%
Answer» B. ± 10%
259.

For closer tolerances which of the following capacitors is usually preferred ?

A. Paper capacitor
B. Mica capacitor
C. Ceramic disc capacitor
D. None of the above
Answer» B. Mica capacitor
260.

The electrostatic force between two charges of one coulomb each and placed at distance of 0.5 m will be

A. 36 x 10fa
B. 36 x 107 N
C. 36 x 108 N
D. 36 x 109 N
Answer» D. 36 x 109 N
261.

The units of volume charge density are

A. Coulomb/metre
B. Coulomb/metre
C. Coulomb/metre
D. Coulomb/metre
Answer» C. Coulomb/metre
262.

"The surface integral of the normal component of the electric displacement D over any closed surface equals the charge enclosed by the surface". The above statement is associated with

A. Gauss's law
B. Kirchhoff s law
C. Faraday's law
D. Lenz's law
Answer» A. Gauss's law
263.

Dielectric strength of mica is

A. 10 to 20 kV/mm
B. 30 to 50 kV/mm
C. 50 to 200 kV/mm
D. 300 to 500 kV/mm
Answer» C. 50 to 200 kV/mm
264.

The dielectric constant (relative permittivity) of glass is given by

A. 0.1 to 0.4
B. 0.5 to 1.0
C. 2.0 to 4.0
D. 5 to 100
Answer» D. 5 to 100
265.

capacitors are mainly used for radio frequency tuning.

A. Paper
B. Air
C. Mica
D. Electrolytic
Answer» B. Air
266.

capacitors can be used only for D.C.

A. Air
B. Paper
C. Mica
D. Electrolytic
Answer» D. Electrolytic
267.

capacitors are used in transistor circuits.

A. Ceramic
B. Paper
C. Air
D. Electrolytic
Answer» A. Ceramic
268.

Capacitors are used for audio frequency and radio frequency coupling and tuning.

A. Air
B. Mica
C. Plastic film
D. Ceramic
Answer» B. Mica
269.

The inverse of capacitance is called

A. reluctance
B. conductance
C. susceptance
D. elastance
Answer» D. elastance
270.

When the dielectric is homogeneous,the potential gradient is

A. uniform
B. non-uniform
C. zero
D. any of the above
Answer» A. uniform
271.

The potential gradient across the material of low permittivity is than across the material of high permittivity.

A. smaller
B. greater
C. both (a) and (b)
D. none of the above
Answer» B. greater
272.

field is associated with the capacitor.

A. Electric
B. Magnetic
C. Both (a) and (b)
D. None of the above
Answer» A. Electric
273.

A capacitor having capacitance of 5 uF is charged to a potential difference of 10,000 V. The energy stored in the capacitor is

A. 50 joules
B. 150 joules
C. 200 joules
D. 250 joules
Answer» D. 250 joules
274.

A single core cable used on 33000 V has conductor diameter 10 mm and the in¬ternal diameter of sheath 25 mm. The maximum electrostatic stress in the cable is

A. 62 x 105 V/m
B. 72 x 105 V/m
C. 82 x 105 V/m
D. 92 x 105 V/m
Answer» B. 72 x 105 V/m
275.

Two infinite parallel plates 10 mm apart have maintained between them a potential difference of 100 V. The acceleration of an electron placed between them is

A. 0.56 x 1015 m/s2
B. 1.5 x 1015 m/s2
C. 1.6 x 1015 m/s2
D. 1.76 x 1015 m/s2
Answer» D. 1.76 x 1015 m/s2
276.

The total deficiency or excess of electrons in a body is known as

A. current
B. voltage
C. potential gradient
D. charge
Answer» D. charge
277.

The relative permittivity has the following units

A. F/m
B. m/F
C. Wb/m
D. no units
Answer» C. Wb/m
278.

The phenomenon of an uncharged body getting charged merely by the nearness of a charged body is known as

A. pholoelectric effect
B. chemical effect
C. magnetic effect
D. induction
Answer» D. induction
279.

A unit tube of flux is known as tube

A. Newton
B. Faraday
C. Michale
D. None of the above
Answer» B. Faraday
280.

The number of Faraday tubes of flux passing through a surface in an electric field is called

A. electric flux
B. electric flux density
C. magnetic flux density
D. electric charge density
Answer» A. electric flux
281.

The unit of electric instensity is

A. N/C2
B. Wb/m2
C. N/C
D. N2/C
Answer» B. Wb/m2
282.

The value of E within the field due to a point charge can be found with the help of

A. Faraday's laws
B. Kirchhoff s laws
C. Coulomb's laws
D. none of the above
Answer» C. Coulomb's laws
283.

at a point may be defined as equal to the lines of force passing normally through a unit cross section at that point.

A. Electric intensity
B. Magnetic flux density
C. Electric flux
D. None of the above
Answer» A. Electric intensity
284.

Electric intensity at any point in an electric field is equal to the at that point.

A. electric flux
B. magnetic flux density
C. potential gradient
D. none of the above
Answer» C. potential gradient
285.

Electric displacement is a quantity.

A. scalar
B. vector
C. both of the above
D. none of the above
Answer» B. vector
286.

at a point is equal to the negative potential gradient at that point.

A. Electric intensity
B. Electric flux
C. Magnetic flux
D. Magnetic flux density
Answer» A. Electric intensity
287.

The unit of dielectric strength is given by

A. V/m
B. V2/m
C. m/V
D. m/V2
Answer» A. V/m
288.

Dielectric stregth______with increasing thickness

A. increases
B. decreases
C. remains unaltered
D. none of the above
Answer» B. decreases
289.

The property of a capacitor to store electricity is called its

A. capacitance
B. charge
C. energy
D. none of the above
Answer» A. capacitance
290.

is that property of a capacitor which delays any change of voltage across it.

A. Inductance
B. Capacitance
C. Potential gradient
D. None of the above
Answer» B. Capacitance
291.

A capacitance of 100 f if is connected in series with a resistance of 8000 £2. The time constant of the circuit is

A. 0.2 s
B. 0.4
C. 0.6 s
D. 0.8 s
Answer» D. 0.8 s
292.

In a cable capacitor, voltage gradient is maximum at the surface of the

A. earth
B. conduction
C. sheath
D. insulator
Answer» B. conduction

Done Studing? Take A Test.

Great job completing your study session! Now it's time to put your knowledge to the test. Challenge yourself, see how much you've learned, and identify areas for improvement. Don’t worry, this is all part of the journey to mastery. Ready for the next step? Take a quiz to solidify what you've just studied.