In a pulsed radar set, the function of the duplexer is to%!

Aid in calibrating the display unit

Prevent frequency drift in the klystron

Allow the transmitter and the receiver to operate from a common antenna

At what position is the input signal inserted into a traveling-wave tube?%!

At the cathode end of the helix

At the collector end of the helix

At the control grid of the electron gun

The coarse frequency adjustment of a reflex klystron is accomplished by%!

An adjustment in the synchronizer

Adjusting the flexible wall of the resonant cavity

An adjustment in the synchronizer

The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the%!

Degree of emission from the cathode

*$_The coarse frequency adjustment of a reflex klystron is accomplished by?

An adjustment in the synchronizer

Adjusting the flexible wall of the resonant cavity

An adjustment in the synchronizer

*$_The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the?

Degree of emission from the cathode

*$_At what position is the input signal inserted into a traveling-wave tube??

At the cathode end of the helix

At the collector end of the helix

At the control grid of the electron gun

*$_In a pulsed radar set, the function of the duplexer is to?

Aid in calibrating the display unit

Prevent frequency drift in the klystron

Allow the transmitter and the receiver to operate from a common antenna

*/*_It is possible to increase the maximum range of a radar equipment by?

Raising the peak power of the transmitter

Narrowing the beam width and increasing the pulse duration

*/*_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space?

Density modulation at the input cavity creates velocity modulation at the output cavity

Frequency modulation at the input cavity creates velocity modulation at the output cavity

Velocity modulation at the input cavity creates density modulation at the output cavity

Density modulation at the input cavity creates velocity modulation at the output cavity

Phase modulation at the input cavity creates velocity modulation at the output cavity.

*/*_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target.?

To the tone of the pulse repetition

Which may be used to tune the radar synchronizer

Which may be used to tune the radar receiver

To the tone of the pulse repetition

Tune the magnetron to the correct frequency

*/*_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be?

A reduction in horizontal resolution

*/*_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is?

A narrow, antenna-beam width in the vertical plane

A narrow, antenna-beam width in the horizontal plane

%_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target._%

To the tone of the pulse repetition

Which may be used to tune the radar synchronizer

Which may be used to tune the radar receiver

To the tone of the pulse repetition

Tune the magnetron to the correct frequency

%_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be_%

A reduction in horizontal resolution

%_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is_%

A narrow, antenna-beam width in the vertical plane

A narrow, antenna-beam width in the horizontal plane

%_It is possible to increase the maximum range of a radar equipment by_%

Raising the peak power of the transmitter

Narrowing the beam width and increasing the pulse duration

%_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space_%

Density modulation at the input cavity creates velocity modulation at the output cavity

Frequency modulation at the input cavity creates velocity modulation at the output cavity

Velocity modulation at the input cavity creates density modulation at the output cavity

Density modulation at the input cavity creates velocity modulation at the output cavity

Phase modulation at the input cavity creates velocity modulation at the output cavity.

_ The aquadag coating on the inside of PPI tube is used$?

To focus the beam of primary electrons

To shield the electron beam from unidirectional magnetic

As a second anode and to prevent the build-up of secondary field

_The frequency of the oscillation generated by a magnetron, is mainly determined by$?

The flux density of the external magnet

The ratio of the dc cathode voltage to the magnetic flux density

The number of the cavity resonators

The dimension of each cavity resonator

_A Class-S Emergency Position-Indicating Radio Beacon (E.P.I.R.B)$?

Must be capable of floating or being secured to a survival

Must have its battery replaced after emergency use

May be tested during the first five minutes of any hour

_The cavity resonator$?

In a reflect klystron has its output taken from the reflector plate

Is equivalent to an LC resonant circuit

In a reflect klystron has its output taken from the reflector plate

Produces a frequency which is independent of the cavity size.

Has a low Q factor for narrow operation.

_A PPI cathode-ray tube as used on a radar set$?

Indicates only the range of a target

Is used to check the percentage of modulation

Indicates both the range and azimuth of a target

Indicates only the range of a target

_In a pulsed radar set, the STC circuit is used to$?

Improve the target bearing resolution

Increases receiver sensitivity for echoes from targets

Vary the pulse frequency in order to control the maximum target

Reduce interference from the effects of sea return

Oscillators of a klystron tube are maintained$?

By bunches of electrons passing the cavity grids

By feedback between the accelerating grid and the repeller

By circulating bunches of electrons within the cavities.

The maximum usable range of the usual radar set (on any particular range setting) is determined by$?

The bandwidth of the receiver IF stages

The width of the transmitted pulses

The interval between transmitted pulses

The bandwidth of the receiver IF stages

69 + Mcqs in Microwave Communication in Electrical Engineering Page 1 McqOptions

1.	A high-power microwave pulse of the order of megawatts can be generated by a%!
A.	Traveling-wave tube
B.	Magnetron
C.	Reflex klystron
D.	Gunn diode
Answer» C. Reflex klystron

Discussion

2.	If k-factor is greater than 1, the array beam is bent%!
A.	Away from the earth
B.	Towards the ionosphere,
C.	Towards the earth
D.	Towards the outer space
Answer» D. Towards the outer space

Discussion

3.	In a pulsed radar set, the function of the duplexer is to%!
A.	Aid in calibrating the display unit
B.	Prevent frequency drift in the klystron
C.	Allow the transmitter and the receiver to operate from a common antenna
D.	All of these
Answer» D. All of these

Discussion

4.	At what position is the input signal inserted into a traveling-wave tube?%!
A.	At the cathode end of the helix
B.	At the collector
C.	At the collector end of the helix
D.	At the control grid of the electron gun
Answer» B. At the collector

Discussion

5.	__________ is the progressive decrease of signal strength with increasing distance.%!
A.	Radiation
B.	Attenuation
C.	Modulation
D.	Propagation
Answer» C. Modulation

Discussion

6.	The coarse frequency adjustment of a reflex klystron is accomplished by%!
A.	The AFC system
B.	Adjusting the flexible wall of the resonant cavity
C.	An adjustment in the synchronizer
D.	Varying the repeller voltage
Answer» C. An adjustment in the synchronizer

Discussion

7.	Which of the reception problems below that is not due to multipath?%!
A.	Delayed spreading
B.	Rayleigh fading
C.	Random Doppler shift
D.	Slow fading
Answer» E.

Discussion

8.	The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the%!
A.	Electron transit time
B.	Distributed lead inductance
C.	Inter-electrode capacitance
D.	Degree of emission from the cathode
Answer» E.

Discussion

9.	*$_The coarse frequency adjustment of a reflex klystron is accomplished by?
A.	The AFC system
B.	Adjusting the flexible wall of the resonant cavity
C.	An adjustment in the synchronizer
D.	Varying the repeller voltage
Answer» C. An adjustment in the synchronizer

Discussion

10.	*$_Which of the reception problems below that is not due to multipath??
A.	Delayed spreading
B.	Rayleigh fading
C.	Random Doppler shift
D.	Slow fading
Answer» E.

Discussion

11.	*$_The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the?
A.	Electron transit time
B.	Distributed lead inductance
C.	Inter-electrode capacitance
D.	Degree of emission from the cathode
Answer» E.

Discussion

12.	*$_At what position is the input signal inserted into a traveling-wave tube??
A.	At the cathode end of the helix
B.	At the collector
C.	At the collector end of the helix
D.	At the control grid of the electron gun
Answer» B. At the collector

Discussion

13.	*$_A high-power microwave pulse of the order of megawatts can be generated by a?
A.	Traveling-wave tube
B.	Magnetron
C.	Reflex klystron
D.	Gunn diode
Answer» C. Reflex klystron

Discussion

14.	*$_If k-factor is greater than 1, the array beam is bent?
A.	Away from the earth
B.	Towards the ionosphere,
C.	Towards the earth
D.	Towards the outer space
Answer» D. Towards the outer space

Discussion

15.	*$_In a pulsed radar set, the function of the duplexer is to?
A.	Aid in calibrating the display unit
B.	Prevent frequency drift in the klystron
C.	Allow the transmitter and the receiver to operate from a common antenna
D.	All of these
Answer» D. All of these

Discussion

16.	*$___________ is the progressive decrease of signal strength with increasing distance.?
A.	Radiation
B.	Attenuation
C.	Modulation
D.	Propagation
Answer» C. Modulation

Discussion

17.	/_What allow microwave to pass in only one direction??
A.	RF emitter
B.	Capacitor
C.	Varactor-triac
D.	Ferrite emitter
Answer» E.

Discussion

18.	/_It is possible to increase the maximum range of a radar equipment by?
A.	Lowering the pulse frequency
B.	Raising the peak power of the transmitter
C.	Narrowing the beam width and increasing the pulse duration
D.	All of these
Answer» E.

Discussion

19.	/_Which causes multipath or frequency selective fading??
A.	Small reflector
B.	Nearer reflector
C.	Further reflector
D.	Large reflector
Answer» E.

Discussion

20.	/_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space?
A.	Frequency modulation at the input cavity creates velocity modulation at the output cavity
B.	Velocity modulation at the input cavity creates density modulation at the output cavity
C.	Density modulation at the input cavity creates velocity modulation at the output cavity
D.	Phase modulation at the input cavity creates velocity modulation at the output cavity.
Answer» C. Density modulation at the input cavity creates velocity modulation at the output cavity

Discussion

21.	/_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna??
A.	Isolator
B.	Magnetron
C.	Simplex
D.	Circulator
Answer» E.

Discussion

22.	/_Which of the following is used as a high power microwave oscillator??
A.	Thyratron
B.	Magnetron
C.	Klystron
D.	Reflex-klystron
Answer» C. Klystron

Discussion

23.	/_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target.?
A.	Which may be used to tune the radar synchronizer
B.	Which may be used to tune the radar receiver
C.	To the tone of the pulse repetition
D.	Tune the magnetron to the correct frequency
Answer» C. To the tone of the pulse repetition

Discussion

24.	/_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be?
A.	A decrease in range
B.	A reduction in horizontal resolution
C.	No noticeable effect
D.	A decrease in gain
Answer» D. A decrease in gain

Discussion

25.	/_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is?
A.	A narrow, antenna-beam width in the vertical plane
B.	A narrow, antenna-beam width in the horizontal plane
C.	A low repetition rate
D.	A high duty cycle
Answer» C. A low repetition rate

Discussion

26.	%_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target._%
A.	Which may be used to tune the radar synchronizer
B.	Which may be used to tune the radar receiver
C.	To the tone of the pulse repetition
D.	Tune the magnetron to the correct frequency
Answer» C. To the tone of the pulse repetition

Discussion

27.	%_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be_%
A.	A decrease in range
B.	A reduction in horizontal resolution
C.	No noticeable effect
D.	A decrease in gain
Answer» D. A decrease in gain

Discussion

28.	%_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is_%
A.	A narrow, antenna-beam width in the vertical plane
B.	A narrow, antenna-beam width in the horizontal plane
C.	A low repetition rate
D.	A high duty cycle
Answer» C. A low repetition rate

Discussion

29.	%_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna?_%
A.	Isolator
B.	Magnetron
C.	Simplex
D.	Circulator
Answer» E.

Discussion

30.	%_It is possible to increase the maximum range of a radar equipment by_%
A.	Lowering the pulse frequency
B.	Raising the peak power of the transmitter
C.	Narrowing the beam width and increasing the pulse duration
D.	All of these
Answer» E.

Discussion

31.	%_Which causes multipath or frequency selective fading?_%
A.	Small reflector
B.	Nearer reflector
C.	Further reflector
D.	Large reflector
Answer» E.

Discussion

32.	%_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space_%
A.	Frequency modulation at the input cavity creates velocity modulation at the output cavity
B.	Velocity modulation at the input cavity creates density modulation at the output cavity
C.	Density modulation at the input cavity creates velocity modulation at the output cavity
D.	Phase modulation at the input cavity creates velocity modulation at the output cavity.
Answer» C. Density modulation at the input cavity creates velocity modulation at the output cavity

Discussion

33.	%_Which of the following is used as a high power microwave oscillator?_%
A.	Thyratron
B.	Magnetron
C.	Klystron
D.	Reflex-klystron
Answer» C. Klystron

Discussion

34.	_ The aquadag coating on the inside of PPI tube is used$?
A.	To focus the beam of primary electrons
B.	To shield the electron beam from unidirectional magnetic
C.	As a second anode and to prevent the build-up of secondary field
D.	All of these
Answer» D. All of these

Discussion

35.	_The frequency of the oscillation generated by a magnetron, is mainly determined by$?
A.	The flux density of the external magnet
B.	The ratio of the dc cathode voltage to the magnetic flux density
C.	The number of the cavity resonators
D.	The dimension of each cavity resonator
Answer» E.

Discussion

36.	_A Class-S Emergency Position-Indicating Radio Beacon (E.P.I.R.B)$?
A.	Must be capable of floating or being secured to a survival
B.	Must have its battery replaced after emergency use
C.	May be tested during the first five minutes of any hour
D.	All of these
Answer» E.

Discussion

37.	_In an SHF pulsed radar set, a reflex klystron can be used as a$?
A.	Single mixer stage
B.	Local oscillator
C.	Transmitter oscillator
D.	Duplexer stage
Answer» C. Transmitter oscillator

Discussion

38.	_The cavity resonator$?
A.	Is equivalent to an LC resonant circuit
B.	In a reflect klystron has its output taken from the reflector plate
C.	Produces a frequency which is independent of the cavity size.
D.	Has a low Q factor for narrow operation.
Answer» B. In a reflect klystron has its output taken from the reflector plate

Discussion

39.	_A PPI cathode-ray tube as used on a radar set$?
A.	Is used to check the percentage of modulation
B.	Indicates both the range and azimuth of a target
C.	Indicates only the range of a target
D.	Is used for receiver alignment
Answer» C. Indicates only the range of a target

Discussion

40.	_In a pulsed radar set, the STC circuit is used to$?
A.	Improve the target bearing resolution
B.	Increases receiver sensitivity for echoes from targets
C.	Vary the pulse frequency in order to control the maximum target
D.	Reduce interference from the effects of sea return
Answer» E.

Discussion

41.	_The main frequency determining element of a klystron is$?
A.	The repeller voltage
B.	The accelerating voltage
C.	Its resonant cavity
D.	Its mode of operation
Answer» D. Its mode of operation

Discussion

42.	_Which of the following is used as an oscillator device in the SHF band?$?
A.	Thyratron tube
B.	Tunnel diode
C.	Klystron tube
D.	Both B and C
Answer» E.

Discussion

43.	_The antenna separations (in meters) required for optimum operation of a space diversity system can be calculated from:where R = effective earth radius (m) and L = path length (m)$?
A.	S = 2≈í¬™R/L
B.	S = 3≈í¬™R/L
C.	S = ≈í¬™R/RL
D.	S = ≈í¬™R/L
Answer» C. S = ≈í¬™R/RL

Discussion

44.	Oscillators of a klystron tube are maintained$?
A.	By bunches of electrons passing the cavity grids
B.	By plate-to-cathode feedback
C.	By feedback between the accelerating grid and the repeller
D.	By circulating bunches of electrons within the cavities.
Answer» B. By plate-to-cathode feedback

Discussion

45.	Rainfall is an important factor for fading of radio waves at frequencies above$?
A.	10 GHz
B.	100 GHz
C.	1 GHz
D.	100 MHz
Answer» B. 100 GHz

Discussion

46.	Which of the following permits a microwave signal to travel in one direction with virtually no loss, but severely attenuates any signal attempting to travel in the reverse direction?$?
A.	Isolator
B.	Wave trap
C.	Tunnel diode
D.	Circulator
Answer» B. Wave trap

Discussion

47.	In microwave transmission using digital radio, what causes most intersymbol interference?$?
A.	Delayed spreading
B.	Rayleigh fading
C.	Random Doppler shift
D.	Slow fading
Answer» B. Rayleigh fading

Discussion

48.	Microwave frequencies are normally regarded as those in the range of$?
A.	1 to 500 MHz
B.	1000 to 10,000 GHz
C.	1 to 100 GHz
D.	10 to 1000 GHz
Answer» D. 10 to 1000 GHz

Discussion

49.	If the duration of the radar transmitted pulse, on a particular range of operation, is increased, the required bandwidth of the receiver‚Äö√Ñ√¥s IF amplifiers$?
A.	Must remain as before
B.	Must be increased
C.	May be decreased
D.	Must be doubled
Answer» D. Must be doubled

Discussion

50.	The maximum usable range of the usual radar set (on any particular range setting) is determined by$?
A.	The width of the transmitted pulses
B.	The interval between transmitted pulses
C.	The bandwidth of the receiver IF stages
D.	The duty cycle
Answer» C. The bandwidth of the receiver IF stages

Discussion

Explore topic-wise MCQs in Electrical Engineering.

A high-power microwave pulse of the order of megawatts can be generated by a%!

If k-factor is greater than 1, the array beam is bent%!

In a pulsed radar set, the function of the duplexer is to%!

At what position is the input signal inserted into a traveling-wave tube?%!

__________ is the progressive decrease of signal strength with increasing distance.%!

The coarse frequency adjustment of a reflex klystron is accomplished by%!

Which of the reception problems below that is not due to multipath?%!

The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the%!

*$_The coarse frequency adjustment of a reflex klystron is accomplished by?

*$_Which of the reception problems below that is not due to multipath??

*$_The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the?

*$_At what position is the input signal inserted into a traveling-wave tube??

*$_A high-power microwave pulse of the order of megawatts can be generated by a?

*$_If k-factor is greater than 1, the array beam is bent?

*$_In a pulsed radar set, the function of the duplexer is to?

*$___________ is the progressive decrease of signal strength with increasing distance.?

*/*_What allow microwave to pass in only one direction??

*/*_It is possible to increase the maximum range of a radar equipment by?

*/*_Which causes multipath or frequency selective fading??

*/*_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space?

*/*_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna??

*/*_Which of the following is used as a high power microwave oscillator??

*/*_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target.?

*/*_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be?

*/*_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is?

%_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target._%

%_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be_%

%_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is_%

%_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna?_%

%_It is possible to increase the maximum range of a radar equipment by_%

%_Which causes multipath or frequency selective fading?_%

%_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space_%

%_Which of the following is used as a high power microwave oscillator?_%

_ The aquadag coating on the inside of PPI tube is used$?

_The frequency of the oscillation generated by a magnetron, is mainly determined by$?

_A Class-S Emergency Position-Indicating Radio Beacon (E.P.I.R.B)$?

_In an SHF pulsed radar set, a reflex klystron can be used as a$?

_The cavity resonator$?

_A PPI cathode-ray tube as used on a radar set$?

_In a pulsed radar set, the STC circuit is used to$?

_The main frequency determining element of a klystron is$?

_Which of the following is used as an oscillator device in the SHF band?$?

_The antenna separations (in meters) required for optimum operation of a space diversity system can be calculated from:where R = effective earth radius (m) and L = path length (m)$?

Oscillators of a klystron tube are maintained$?

Rainfall is an important factor for fading of radio waves at frequencies above$?

Which of the following permits a microwave signal to travel in one direction with virtually no loss, but severely attenuates any signal attempting to travel in the reverse direction?$?

In microwave transmission using digital radio, what causes most intersymbol interference?$?

Microwave frequencies are normally regarded as those in the range of$?

If the duration of the radar transmitted pulse, on a particular range of operation, is increased, the required bandwidth of the receiver‚Äö√Ñ√¥s IF amplifiers$?

The maximum usable range of the usual radar set (on any particular range setting) is determined by$?

/_What allow microwave to pass in only one direction??

/_It is possible to increase the maximum range of a radar equipment by?

/_Which causes multipath or frequency selective fading??

/_As the electron beam moves through a klystron‚Äö√Ñ√¥s intercavity drift space?

/_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna??

/_Which of the following is used as a high power microwave oscillator??

/_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target.?

/_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be?

/_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is?