Test: Electromagnetic Field Theory - 4

Question 1

Which of the following laws of electromagnetic theory is associated with the force experienced by two loops of a wire carrying currents?

Accepted Answer

Ampere's law

Answer

Maxwell's law

Answer

Coulomb's law

Answer

Laplace's law

Question 2

The intrinsic impedance of free space

Accepted Answer

is independent of frequency

Answer

increases with increase of frequency

Answer

decreases with increase of frequency

Answer

none

Question 3

To couple a coaxial line to a parallel to wire line it is best to use a

Accepted Answer

balun

Answer

slotted line

Answer

directional coupler

Answer

quarter wave transformer

Question 4

The shunt admittance of a transmission line is given by

Accepted Answer

γ = G + jωC

Answer

γ = R + jωL

Answer

γ = R - jωL

Answer

γ = jωGC

Question 5

A dipole antenna was radiating with some excitation in free space radiating a certain amount of the power. If this antenna is immersed in a lake where water is non-dissipative but has a dielectric constant of 81, the radiated power with the same excitation will

Accepted Answer

remain the same

Answer

decrease to finite non-zero value

Answer

increase

Answer

decrease to zero

Question 6

If short-circuited and open circuited impedances are 5 ohms and 20 ohms, then characteristic impedance is

Accepted Answer

10 ohms

Answer

1 ohms

Answer

25 ohms

Answer

100 ohms

Question 7

Electric lines of force do not cross each other because

Accepted Answer

the tangent to the line of force gives the direction of E and if they cross two tangents for E which is not possible

Answer

the lines of force mutually repel each other

Answer

the lines of force emanate from a point charge

Answer

none of the above

Question 8

A person with a receiver is 5 km away from the transmitter. What is the distance that this person must move further to detect at 3 dB decrease in signal strength?

Accepted Answer

2070 m

Answer

942 m

Answer

4978 m

Answer

5320 m

Question 9

For free space propagation

Accepted Answer

γ = a + jβ

Answer

γ = jβ

Answer

γ = a

Answer

a = β = 0

Question 10

SHF range is

Accepted Answer

3000 - 30000 MHz

Answer

30 - 300 MHz

Answer

300 - 3000 MHz

Answer

30000 - 300000 MHz

Question 11

For an ideal antenna, numerical value of directivity must be

Accepted Answer

∞

Answer

0

Answer

1

Answer

any value

Question 12

The force in a magnetic field is given by F = qvB

Accepted Answer

F and q are perpendicular and v and B are perpendicular

Answer

F and q only are perpendicular to each other

Answer

F and v, F and B are mutually perpendicular to each other and v and B at any angle between them

Answer

All the four components are perpendicular to each other

Question 13

An electromagnetic wave is incident normally on a dielectric boundary. It is

Accepted Answer

partially reflected and partially refracted

Answer

totally reflected

Answer

totally absorbed

Answer

none of the above

Question 14

According to maximum power transfer theorem, if the load is inductive, the source should be

Accepted Answer

capacitive

Answer

inductive

Answer

resistive

Answer

any of the above

Question 15

According to Siegel and Labus, antenna can be treated as

Accepted Answer

opened-out transmission line

Answer

closed transmission line

Answer

shorted transmission line

Answer

earthed transmission line

Question 16

The value of susceptibility in case of vacuum is taken as

Accepted Answer

zero

Answer

0.5

Answer

unity

Answer

infinity

Question 17

Given figure shows a 90º sector of spherical reflector with vertex 'V', centre of curvature 'C' and equal distances VD, DF, FE and EC. When a beam of EM wave is incident parallel to the axis, all the energy will pass through the region

Accepted Answer

EC

Answer

VD

Answer

DF

Answer

EF

Question 18

Self impedance is

Accepted Answer

same for transmitting (T_t) and receiving antenna (T_r)

Answer

Tt > Tr

Answer

Tr > Tt

Answer

no relation

Question 19

Equipotential surfaces about a point charge are in which one of the following forms?

Accepted Answer

Sphere

Answer

Planes

Answer

Cylinders

Answer

Cubes

Question 20

__________ will have the least value of relative permeability.

Accepted Answer

Silver

Answer

Palladium

Answer

Cobalt

Answer

Iron

Question 21

The relative permeability is taken as unity for which of the following?

Accepted Answer

Air

Answer

Cobalt

Answer

Vacuum

Answer

Bismuth

Question 22

The disturbance from adjacent power lines is known as

Accepted Answer

inductive disturbance

Answer

cross talk

Answer

cross fire

Answer

none of the above

Question 23

Which of the following term applies to troposcatter propagation?

Accepted Answer

Fading

Answer

SIDs

Answer

Faraday rotation

Answer

Atmospheric storms

Question 24

Magnesium is alloyed with conducting materials for antenna primarily with the purpose of

Accepted Answer

reducing weight

Answer

increasing efficiency

Answer

improving radiative power

Answer

increasing density

Question 25

Two co-axial cylindrical sheets of charge are present in free space f_s = 5 c/m² at r = 2 m and r_s = -2 c/m² at r = 4 m, The displacement flux density at r = 3 m is

Accepted Answer

Answer

Answer

Answer

Electromagnetic Field Theory - 4 - Free MCQ Practice Test with solutions,

MCQ Practice Test & Solutions: Test: Electromagnetic Field Theory - 4 (25 Questions)

Which of the following laws of electromagnetic theory is associated with the force experienced by two loops of a wire carrying currents?

The intrinsic impedance of free space

To couple a coaxial line to a parallel to wire line it is best to use a

The shunt admittance of a transmission line is given by

A dipole antenna was radiating with some excitation in free space radiating a certain amount of the power. If this antenna is immersed in a lake where water is non-dissipative but has a dielectric constant of 81, the radiated power with the same excitation will

If short-circuited and open circuited impedances are 5 ohms and 20 ohms, then characteristic impedance is

Electric lines of force do not cross each other because

A person with a receiver is 5 km away from the transmitter. What is the distance that this person must move further to detect at 3 dB decrease in signal strength?

For free space propagation

SHF range is

For an ideal antenna, numerical value of directivity must be

The force in a magnetic field is given by F = qvB

An electromagnetic wave is incident normally on a dielectric boundary. It is

According to maximum power transfer theorem, if the load is inductive, the source should be

According to Siegel and Labus, antenna can be treated as

The value of susceptibility in case of vacuum is taken as

Given figure shows a 90º sector of spherical reflector with vertex 'V', centre of curvature 'C' and equal distances VD, DF, FE and EC. When a beam of EM wave is incident parallel to the axis, all the energy will pass through the region

Self impedance is

Equipotential surfaces about a point charge are in which one of the following forms?

__________ will have the least value of relative permeability.

The relative permeability is taken as unity for which of the following?

The disturbance from adjacent power lines is known as

Which of the following term applies to troposcatter propagation?

Magnesium is alloyed with conducting materials for antenna primarily with the purpose of

Two co-axial cylindrical sheets of charge are present in free space f_s = 5 c/m² at r = 2 m and r_s = -2 c/m² at r = 4 m, The displacement flux density at r = 3 m is

Electromagnetics

Electromagnetics

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Electromagnetic Field Theory - 4 - Free MCQ Practice Test with solutions,

MCQ Practice Test & Solutions: Test: Electromagnetic Field Theory - 4 (25 Questions)

Which of the following laws of electromagnetic theory is associated with the force experienced by two loops of a wire carrying currents?

The intrinsic impedance of free space

To couple a coaxial line to a parallel to wire line it is best to use a

The shunt admittance of a transmission line is given by

A dipole antenna was radiating with some excitation in free space radiating a certain amount of the power. If this antenna is immersed in a lake where water is non-dissipative but has a dielectric constant of 81, the radiated power with the same excitation will

If short-circuited and open circuited impedances are 5 ohms and 20 ohms, then characteristic impedance is

Electric lines of force do not cross each other because

A person with a receiver is 5 km away from the transmitter. What is the distance that this person must move further to detect at 3 dB decrease in signal strength?

For free space propagation

SHF range is

For an ideal antenna, numerical value of directivity must be

The force in a magnetic field is given by F = qvB

An electromagnetic wave is incident normally on a dielectric boundary. It is

According to maximum power transfer theorem, if the load is inductive, the source should be

According to Siegel and Labus, antenna can be treated as

The value of susceptibility in case of vacuum is taken as

Given figure shows a 90º sector of spherical reflector with vertex 'V', centre of curvature 'C' and equal distances VD, DF, FE and EC. When a beam of EM wave is incident parallel to the axis, all the energy will pass through the region

Self impedance is

Equipotential surfaces about a point charge are in which one of the following forms?

__________ will have the least value of relative permeability.

The relative permeability is taken as unity for which of the following?

The disturbance from adjacent power lines is known as

Which of the following term applies to troposcatter propagation?

Magnesium is alloyed with conducting materials for antenna primarily with the purpose of

Two co-axial cylindrical sheets of charge are present in free space fs = 5 c/m2 at r = 2 m and rs = -2 c/m2 at r = 4 m, The displacement flux density at r = 3 m is

Electromagnetics

Electromagnetics

Top Courses for Electronics and Communication Engineering (ECE)

About this Electronics and Communication Engineering (ECE) Practice Test

Explore more Electronics and Communication Engineering (ECE) Study Resources

Two co-axial cylindrical sheets of charge are present in free space f_s = 5 c/m² at r = 2 m and r_s = -2 c/m² at r = 4 m, The displacement flux density at r = 3 m is