MCQOPTIONS
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MCQOPTIONS
This section includes 9294 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 8701. |
A directional coupler is used |
| A. | to transmit microwave signals |
| B. | to generate microwave signals |
| C. | to measure amplitude and phase of a travelling wave |
| D. | both (a) and (b) |
| Answer» D. both (a) and (b) | |
| 8702. |
Consider the following statements about a magic tee The collinear arms are isolated from each other.On of the collinear arms is isolated from E arm.On of the collinear arms is isolated from H arm.E and H arms are isolated from each other. Of the above statements |
| A. | 1 and 2 are correct |
| B. | 1 and 3 are correct |
| C. | 1 and 4 are correct |
| D. | 2 and 3 are correct |
| Answer» D. 2 and 3 are correct | |
| 8703. |
Assertion (A): Hollow waveguides are frequently used as transmission lines at microwave frequencies.Reason (R): Waveguide has high power handling capacity, low loss and simple structure. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 8704. |
Dielectric constant and conductivity of rocky soil and flat sandy soil are around |
| A. | 10 and 20 mho/cm respectively |
| B. | 20 and 10 mho/cm respectively |
| C. | 2 and 5 mho/cm respectively |
| D. | 0.5 and 2 mho/cm respectively |
| Answer» B. 20 and 10 mho/cm respectively | |
| 8705. |
Assertion (A): In rectangular waveguide TE01 mode is just TE10 mode rotated by 90 .Reason (R): When a rectangular waveguide is rotated by 90 , the broad and narrow dimensions get interchanged. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 8706. |
Consider the following statements about directional coupler shown in the figure Ports 1 and 2 are decouplePorts 3 and 4 are decoupledPots 1 and 3 are decoupledPorts 1 and 4 are decoupled Which of the above statements are correct? |
| A. | 1 and 2 only |
| B. | 3 and 4 only |
| C. | 1, 2 and 3 |
| D. | 2, 3 and 4 |
| Answer» B. 3 and 4 only | |
| 8707. |
A 'rat race' is a |
| A. | hybrid junction for microwaves |
| B. | a microwave oscillator |
| C. | a microwave amplifier |
| D. | a microwave antenna |
| Answer» B. a microwave oscillator | |
| 8708. |
At a frequency equal to cutoff frequency in a rectangular wave guide |
| A. | the flow of electromagnetic energy is zero |
| B. | the flow of electromagnetic energy is infinite |
| C. | the flow of electromagnetic energy is 50% of maximum |
| D. | the flow of electromagnetic energy is 10% of maximum |
| Answer» C. the flow of electromagnetic energy is 50% of maximum | |
| 8709. |
Two identical hybrid tees are joined as shown in the given figure. If 16 mW power is fed into port 1, the power output at ports 2 , 3, 1', 2', 3' respectively is |
| A. | 8, 4, 2, 2, 0 mW |
| B. | 0, 8, 4, 4, 0 mW |
| C. | 0, 8, 2, 2, mW |
| D. | 8, 2, 4, 2, 0 mW |
| Answer» C. 0, 8, 2, 2, mW | |
| 8710. |
Assertion (A): An artificial transmission line can be used as a pulse generator.Reason (R): A pulse function is used very frequently in network analysis. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» C. A is correct but R is wrong | |
| 8711. |
TE10 mode of propagation of electromagnetic energy in waveguides can be thought of as |
| A. | three TEM waves travelling along length of wave-guide |
| B. | One TEM wave travelling along length of wave guide and one TEM wave propagation in the transverse plane |
| C. | One TEM wave travelling along the length of wave guide and two TEM waves |
| D. | none of the above |
| Answer» D. none of the above | |
| 8712. |
The main advantage of using micro waves for communications is |
| A. | large bandwidth |
| B. | small bandwidth |
| C. | low power |
| D. | high power |
| Answer» B. small bandwidth | |
| 8713. |
In a microwave resistor the wall thickness is made as small as possible to |
| A. | have high value of R |
| B. | have low value of R |
| C. | minimize capacitive effect |
| D. | reduce inductance |
| Answer» D. reduce inductance | |
| 8714. |
In a klystron amplifier the transit time of electron passing the gap in the cavity should be |
| A. | less than one cycle |
| B. | less than half cycle |
| C. | less than quarter cycle |
| D. | more than quarter cycle |
| Answer» D. more than quarter cycle | |
| 8715. |
In fibre optics the use is made of thin glass fibres for efficient transmission of light. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8716. |
In a backward wave oscillator the efficiency |
| A. | is much higher than in TWT |
| B. | is much lower than in TWT |
| C. | is almost the same as in TWT |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 8717. |
Consider the following statements Fading of signals is generally greatest near radio horizon.Fading of signals is generally greatest in shadow zone.Fading is small when a good optical path is present. Which of the above statements are correct? |
| A. | 1, 2 and 3 |
| B. | 1 and 2 only |
| C. | 1 and 3 only |
| D. | 2 and 3 only |
| Answer» B. 1 and 2 only | |
| 8718. |
In p mode of operation of magnetron the spikes due to phase focussing effect rotate at an angular velocity corresponding to |
| A. | one pole/cycle |
| B. | two pole/cycle |
| C. | four pole/cycle |
| D. | six pole/cycle |
| Answer» C. four pole/cycle | |
| 8719. |
In microwave system, waveguide twists |
| A. | change the plane of polarization of a propagating wave |
| B. | change the direction of a propagating wave |
| C. | change the mode of a propagating wave |
| D. | both (b) and (c) |
| Answer» B. change the direction of a propagating wave | |
| 8720. |
Microwaves |
| A. | get reflected by ionosphere |
| B. | are absorbed by ionosphere |
| C. | are neither reflected nor absorbed by ionosphere |
| D. | are both reflected and absorbed by ionosphere |
| Answer» D. are both reflected and absorbed by ionosphere | |
| 8721. |
A line of length less than and open circuited at far end behaves as |
| A. | inductance L |
| B. | capacitance C |
| C. | L and C in series |
| D. | L and C in parallel |
| Answer» C. L and C in series | |
| 8722. |
Consider the following statements about hybrid ring Ports 1 and 2 are decoupled.Port 3 and 4 are coupled.A signal entering either port 1 or 2 splits equally between ports 3 and 4.A signal entering either port 3 or 4 splits equally between ports 1 and 2. Which of the above are correct? |
| A. | 1, 2, 3 and 4 |
| B. | 1, 3 and 4 |
| C. | 1 and 2 |
| D. | 2, 3 and 4 |
| Answer» C. 1 and 2 | |
| 8723. |
Guide wavelength ( g), cutoff wavelength ( c) and free space wavelength ( 0) of a waveguide are related as |
| A. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/16-166-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/16-166-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/16-166-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/16-166-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/16-166-2.png"> | |
| 8724. |
Which of the following is used in integrated circuits? |
| A. | Microstrip line |
| B. | Coaxial line |
| C. | Twin wire line |
| D. | Shield cable |
| Answer» B. Coaxial line | |
| 8725. |
Which of the following is a balanced line? |
| A. | Coaxial line |
| B. | Strip line |
| C. | Microstrip line |
| D. | TV twin lead |
| Answer» E. | |
| 8726. |
In the given figure power meters at A and B indicate 1 mW and 110 W respectively. VSWR of line is |
| A. | 1.5 |
| B. | 2 |
| C. | 2.5 |
| D. | 3 |
| Answer» C. 2.5 | |
| 8727. |
As frequency is increased, the skin effect |
| A. | increases |
| B. | decreases |
| C. | remains the same |
| D. | either (b) or (c) |
| Answer» B. decreases | |
| 8728. |
In microstrip line has dielectric material most commonly used is |
| A. | silicon |
| B. | rubber |
| C. | plastic |
| D. | bakelite |
| Answer» B. rubber | |
| 8729. |
Klystron amplifier is not used to amplifier very weak microwave signals due to |
| A. | low gain for weak signals |
| B. | low noise for weak signals |
| C. | high noise |
| D. | both (a) and (b) |
| Answer» D. both (a) and (b) | |
| 8730. |
Interference generated by electrical equipment and automobile ignition systems when observed closed to earth is |
| A. | horizontally polarized |
| B. | vertically polarized |
| C. | polarized both horizontally |
| D. | not polarized |
| Answer» C. polarized both horizontally | |
| 8731. |
A rectangular waveguide has two stubs each length connected at the source end. The stubs are short circuted. Then |
| A. | the longitudinal current is power current and current in stubs is reactive |
| B. | the longitudinal current is reactive current and current in stubs is power current |
| C. | both power and reactive exists in both longitudinal direction and stubs |
| D. | the current in stubs is zero |
| Answer» B. the longitudinal current is reactive current and current in stubs is power current | |
| 8732. |
A transmission line discontinuity is defined as any interruption in the uniformity of the line. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8733. |
The earliest uses of electromagnetic waves were |
| A. | point to point communication |
| B. | radar |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 8734. |
In terms of R, L, G and C the propagation constant of a transmission line is |
| A. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/09-19-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/09-19-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/09-19-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/09-19-4.png"> |
| Answer» C. <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/09-19-3.png"> | |
| 8735. |
Consider the following statements (L is the length of array between centres of end antennas and A is wave-length)Width of major lobe between nulls of broad side array and end fire array are different.Directive gain of broadside array and end fire array are different.Directive gain of broadside array is 4 Which of the above statements are correct? |
| A. | 1, 2 and 3 |
| B. | 1 and 2 only |
| C. | 1 only |
| D. | 1 and 3 only |
| Answer» E. | |
| 8736. |
The electrical requirement on wall thickness of rectangular wave guide is |
| A. | wall thickness is more than skin depth |
| B. | wall thickness is less than skin depth |
| C. | wall thickness is equal to skin depth |
| D. | either (b) or (c) |
| Answer» B. wall thickness is less than skin depth | |
| 8737. |
If a microstrip is enclosed in a metal enclosure |
| A. | the radiation losses are increased |
| B. | the radiation losses are reduced RL |
| C. | the capacitance becomes zero |
| D. | the inductance becomes zero |
| Answer» C. the capacitance becomes zero | |
| 8738. |
Both Impatt and Trapatt devices use avalanche effect |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8739. |
Match the following: List I (Library function in Pascal) List II (Type of argument)A.ROUND X1.X in radiansB.ABS X2.X realC.SQR X3.X real or integerD.SIN X |
| A. | A-2, B-3, C-3, D-1 |
| B. | A-2, B-3, C-1, D-3 |
| C. | A-3, B-2, C-2, D-1 |
| D. | A-2, B-3, C-2, D-1 |
| Answer» B. A-2, B-3, C-1, D-3 | |
| 8740. |
In a TWT the amplitude of resultant wave travelling down the helix |
| A. | increases exponentially |
| B. | increases linearly |
| C. | decreases exponentially |
| D. | is almost constant |
| Answer» B. increases linearly | |
| 8741. |
Match the following: List I (Network parameter) List II (Measured under open-circuit conditions) A.Z111.B.A2.C.C3.D.Z224. |
| A. | A-1, B-4, C-2, D-3 |
| B. | A-3, B-4, C-2, D-1 |
| C. | A-1, B-2, C-4, D-3 |
| D. | A-3, B-2, C-4, D-1 |
| Answer» E. | |
| 8742. |
Match the following: List I f(t) List II F (s)A.cos t1.B.sin t2.C.cosh t3.D.sinh t4. |
| A. | A-1, B-3, C-2, D-4 |
| B. | A-4, B-2, C-1, D-3 |
| C. | A-4, B-3, C-1, D-2 |
| D. | A-3, B-2, C-1, D-4 |
| Answer» D. A-3, B-2, C-1, D-4 | |
| 8743. |
Microwave resonators are used in |
| A. | microwave oscillators |
| B. | microwave narrow band amplifier |
| C. | microwave frequency metres |
| D. | all of the above |
| Answer» E. | |
| 8744. |
Assertion (A): TWT uses a focussing mechanism to prevent the electron beam from spreading.Reason (R): In a TWT the electron beam has to travel a much longer distance than in klystron. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 8745. |
Match the following: List I List II A.Resistance1.Current noiseB.Diode2.Partition noiseC.Triode3.Shot noiseD.p-n junction4.Atmospheric noise 5.Johnson noise |
| A. | A-5, B-3, C-2, D-1 |
| B. | A-1, B-2, C-3, D-5 |
| C. | A-3, B-5, C-1, D-2 |
| D. | A-3, B-5, C-2, D-1 |
| Answer» B. A-1, B-2, C-3, D-5 | |
| 8746. |
Match the following: List I (Command in WORD) List II (Meaning) A.END1.The bar displays the current position of cursorB.HOME2.Moves cursor to the beginning of current lineC.Status3.Moves cursor to end of document |
| A. | A-1, B-2, C-3 |
| B. | A-3, B-1, C-2 |
| C. | A-2, B-3, C-1 |
| D. | A-3, B-2, C-1 |
| Answer» E. | |
| 8747. |
Match the following: List I (Laws of Boolean) List II (Relation algebra) A.Distributive law1.x + x = xB.DeMorgans law2.x(y + z) = xy + xzC.Idempotent law3.(x) = xD.Involution law4.(x + y) = xy |
| A. | A-1, B-2, C-3, D-4 |
| B. | A-2, B-4, C-1, D-3 |
| C. | A-3, B-4, C-1, D-2 |
| D. | A-4, B-1, C-2, D-3 |
| Answer» C. A-3, B-4, C-1, D-2 | |
| 8748. |
Match the following: List I (fk) List II [F(z)] A.11.B.kn2.(1 - az-1)-1C.ak3.- ln (1 - z-1)-1D.4.(1 - z-1)-1 |
| A. | A-1, B-4, C-2, D-3 |
| B. | A-2, B-3, C-1, D-4 |
| C. | A-4, B-1, C-2, D-3 |
| D. | A-1, B-4, C-3, D-2 |
| Answer» D. A-1, B-4, C-3, D-2 | |
| 8749. |
Match the following: List I List II A.p type semiconductor1.siliconB.n type semiconductor2.holes are majority carriersC.Intrinsic semiconductor3.electrons are majority carriersD.Tungsten4.is a metal |
| A. | A-2, B-3, C-1, D-4 |
| B. | A-1, B-2, C-3, D-4 |
| C. | A-4, B-3, C-2, D-1 |
| D. | A-3, B-1, C-2, D-4 |
| Answer» B. A-1, B-2, C-3, D-4 | |
| 8750. |
Match the following: List I List II A.Resistance1.M-1L-2T2I2B.Inductance2.ML2T-2I-2C.Capacitance3.M-1L-2T4I2D.Reluctance4.ML2T-3I-2 |
| A. | A-1, B-2, C-3, D-4 |
| B. | A-2, B-1, C-3, D-4 |
| C. | A-4, B-2, C-3, D-1 |
| D. | A-2, B-4, C-3, D-1 |
| Answer» D. A-2, B-4, C-3, D-1 | |