# Electrical engineering-Microwave Engineering MCQs Set/8 Sample Test,Sample questions

1.2.81 cm

2.3 cm

3.2 cm

4.3.4 cm

1.True

2.False

1.True

2. False

1.True

2.False

## Question: ```A major challenge in designing a radiometer is: ```

1.Design complexity

2.High cost

4.None of the mentioned

1.18 m

2. 13 m

3.16.4 m

4.17.3 m

1.True

2.False

1.-110 dBm

2.-234 dBm

3. -145 dBm

4.-124 dBm

1.1

2.2

3.4

4.8

1.1.5

2.3

3.2.5

4.3.5

## Question: ```A typical radiometer would measure the brightness temperature over the range of about: ```

1.50-300 K

2.100-200 K

3.400-500 K

4.None of the mentioned

## Question: ```A ________ determines the target range by measuring the round trip time of a pulsed microwave signal. ```

4.None of the mentioned

## Question: ```A __________ is a device that converts a guided electromagnetic wave on a transmission line into a plane wave propagating in free space. ```

1.Transmitting antenna

2.Receiving antenna

4.Mixer

1.True

2.False

## Question: ```Advantage of HJT over BJT is that it has: ```

1.higher gain

2.high frequency of operation

3.sophisticated construction

4.none of the mentioned

## Question: ```All modern wireless communication systems rely on digital modulation methods due to: ```

1.superior performance

2.low power requirements

3.sustainability

4. all of the mentioned

## Question: ```An antenna source that radiates energy uniformly in all the directions is called: ```

1.Isotropic source

2.Anisotropic source

3.Point source

4. None of the mentioned

1.840 K

2.762 K

3.678 K

4. 1236 K

## Question: ```Antenna that does not belong to the horn antenna family among the following are: ```

1.Pyramidal horn

2.Conical horn

3.bi-conical horn

4.None of the mentioned

1.True

2.False

## Question: ```Antennas having a constant pattern in the azimuthal plane are called _____________ ```

1.High gain antenna

2.Omni directional antenna

3.Unidirectional antenna

4.Low gain antenna

1.True

2. False

## Question: ```As the beam area of an antenna decreases, the directivity of the antenna: ```

1.Increases

2.Decreases

3.Remains unchanged

4.Depends on the type of the antenna

1.True

2.False

1.True

2.False

## Question: ```Bluetooth devices operate at a frequency of : ```

1.2.4 GHz

2.4.5 GHz

3.5.7 GHz

4.none of the mentioned

1.True

2.False

## Question: ```Dipole antennas are an example for: ```

1.Wire antennas

2. Aperture antennas

3.Array antennas

4.None of the mentioned

1.True

2.False

1.True

2. False

1.True

2.False

1.True

2.False

## Question: ```Given that the antenna efficiency is 0.9, equivalent brightness temperature is 200 K; physical temperature is 300 K, noise temperature of an antenna is: ```

1.220 K

2.210 K

3. 240 K

4.None of the mentioned

1.12

2.24

3. 36

4.48

1.true

2.false

1.true

2.false

## Question: ```High directivity required in RADAR communication is satisfied using this type of antennas: ```

1.Wide band antennas

2.Antenna arrays

3.Slot antennas

4.Patch antennas

## Question: ```Ideally, the number of point sources an antenna can resolve is numerically equal to: ```

1.Gain of the antenna

2.Directivity

3.Beam efficiency

4.Beam area

1.-90 dBm

2.-115 dBm

3.-56 dBm

4.-120 dBm

1.60 MHz

2.45.6 GHz

3.66.3 GHz

4. 34.8 GHz

1.Two

2.Four

3.Three

4. One

1.24

2.18

3.36

4.12

1.108 dB

2.12 dB

3. 45 dB

4.48 dB

## Question: ```If the power input to an antenna is 100 mW and if the radiated power is measured to be 90 mW, then the efficiency of the antenna is: ```

1.75 %

2.80 %

3. 90 %

4.Insufficient data

1.45 dB

2.-195 dB

3.-35 dB

4.35 dB

1.30 dB

2.-30 dB

3.35 dB

4.-35 dB

1.True

2.False

1.1163 K

2. 1789 K

3.1000 K

4.1234 K

1.True

2.False

## Question: ```In this method of wireless communication, communication happens only in one direction: ```

1.Simplex

2.Duplex

3.Half duplex

4.None of the mentioned

## Question: ```Lens antennas are classified into two types. One being fast antenna, the other one is: ```

1.Slow antenna

2.Delay antenna

3.Dynamic antenna

4.None of the mentioned

1.True

2.False

1.True

2.False

## Question: ```Most of the wireless systems today operate at a frequency of about: ```

1.800 MHz

2.100 MHz

3.80 MHz

4.None of the mentioned

1.True

2.False

## Question: ```Patch antennas are the antennas of small size and are made of: ```

1.Strip line

2.Microstrip lines

3.Coaxial cables

4.Rectangular waveguide

1.True

2.False

1.true

2.false

1.true

2.false

1.8114 m

2.2348 m

3.1256 m

4.4563 m

1.True

2.False

1.True

2.False

1.True

2.False

## Question: ```The amount of power by which the received power must be greater than the threshold level required to maintain a minimum quality of service is called _______ ```

1.Line loss

4.None of the mentioned

## Question: ```The antenna in which location of the feed determines the direction of the lobe are: ```

1.Wire antenna

2.Loop antenna

3.Helical antenna

4. Horn antenna

## Question: ```The antennas which offer high operational bandwidth and the antenna parameters are maintained over a wide range of antennas are called: ```

1.Wide band antennas

2.Array antennas

3.Parabolic antennas

4.None of the mentioned

## Question: ```The basic equation of radiation that is applied to any antenna irrespective of the type of the antenna is: ```

1.iL= Qv

2.iQ = Lv

3.i/L=Q/v

4.None of the mentioned

## Question: ```The basic requirements of transmitting antennas are: ```

1.High efficiency

2.Low side lobes

3.Large signal to noise ratio

4.Lone of the mentioned

## Question: ```The beam width of the antenna pattern measured at half power points is called: ```

1.Half power beam width

2.Full null beam width

3.Beam width

4. None of the mentioned

## Question: ```The current gain of a BJT ________ with frequency. ```

1.increases

2.decreases

3.remains constant

4.none of the mentioned

## Question: ```The dominant factor affecting the accuracy of the total power radiometer is the variation of ___________ ```

1.Gain in the overall system

2.The feedback circuit

3.Efficiency of the system

4.None of the mentioned

1.23

2.25

3.14

4.27

1.true

2.false

1.True

2.False

1.Loop antennas

2.Wire antennas

3.Dipole antenna

4.Slot antennas

2.BPSK

3.QAM

4.QPSK

1.True

2.False

## Question: ```The noise temperature of an antenna is given by the expression: ```

4.None of the mentioned

## Question: ```The number N of radio transmitters or point sources of radiation distributed uniformly over the sky which an antenna can resolve is given by: ```

4.None of the mentioned

1.Three

2.Four

3.Two

4.Five

1.true

2.false

## Question: ```The pattern of the reflector in a reflector antenna is called: ```

1.Primary pattern

2.Secondary pattern

3.Reflector pattern

4.None of the mentioned

1.true

2.false

## Question: ```The receiver model of a total power radiometer is based on the: ```

4.None of the mentioned

## Question: ```The solid area through which all the power radiated by the antenna is: ```

1.Beam area

2.Effective area

3.Aperture area

4.Beam efficiency

## Question: ```The system bandwidth of a total power radiometer is determined by the: ```

1.RF amplifier

2. Local oscillator

3. IF filter

4.IF amplifier

## Question: ```The term radar cross section defines the: ```

1.Scattering ability of the target

3.Amount of energy scattered by unwanted objects

4.Cross section of radar area through which energy is emitted

## Question: ```The terminal impedance of a dipole antenna is 710 Î©. The terminal impedance of the slot antenna given the intrinsic impedance of air is 377 Î© is: ```

4.None of the mentioned

1.true

2.false

1.True

2.False

1.true

2.false

## Question: ```_____ is a device that produces a phase shift of a required amount of the input wave. ```

1.Phase shifter

2.Attenuator

3.Resonator

4. None of the mentioned

## Question: ```______ antennas have gain less than reflector antennas but have more lenient tolerance on surfaces. ```

1.Helical antennas

2.Lens antennas

3.Array antennas

4.Slot antennas

## Question: ```_______ of an antenna is defined as the ratio of the induced voltage to the incident electric field. ```

1.Effective height

2.Gain

3. Directivity

4.Loss

## Question: ```________ of an antenna is a plot of the magnitude of the far field strength versus position around the antenna. ```

2.Directivity

3.Beam width

4.None of the mentioned

## Question: ```_________ antennas consist of a regular arrangement of antenna elements with a feed network ```

1.Aperture antennas

2.Array antennas

3.Printed antennas

4.Wire antennas

1.White noise

2.Gaussian noise

3.Thermal noise

4.Shot noise

## Question: ```_________ is a device that converts electrons to photons or vice-versa. ```

1.Antenna

2.Electron gun

3.Photon amplifier

4.Microwave tube

## Question: ```__________ system obtains information about a target by transmitting a signal and receiving the echo from the target. ```

2.Sonar

4.None of the mentioned

## More MCQS

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