Antenna and Wave Propagation 4

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Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Antenna and Wave Propagation 4

Part 4: List for questions and answers of Antenna & wave Propagation

 

Q1. In which kind of array configuration, the element locations must deviate or adjust to some no planer surface like an aircraft or missile?

a) Linear

b) Planer

c) Conformal

d) All of the above

 

Q2. According to the directivity of a small loop, which value of θ  contributes to achieve the maximum value of radiation intensity (Umax)?

a) 0°

b) 90°

c) 180°

d) 270°

 

Q3. From the radiation point of view, small loops are _________radiators

a) Poor

b) Good

c) Better

d) Excellent

 

Q4. In electrically small loops, the overall length of the loop is ______ one-tenth of a wavelength

a) Less than

b) Equal to

c) Greater than

d) None of the above

 

Q5. Which pattern is generated due to plotting of square of amplitude of an electric field?

a) Field Pattern

b) Voltage Pattern

c) Power Pattern

d) All of the above

 

Q6. In flared transmission line, the radiation phenomenon increases due to ________ in flaring

a) Increase

b) Decrease

c) Stability

d) None of the above 

 

Q7. How are the infinitesimal dipoles represented in terms of antenna length and signal wavelength?

a) l less than & equal to (λ  /50)

b) (λ /50 ) less than l less than & equal to (λ /10)

c) l = λ /2

d) None of the above

 

Q8. Which waveform plays a crucial role in determining the radiation pattern of the dipole/wire antennas?

a) Current

b) Voltage

c) Frequency

d) Phase

 

Q9. Which operations are performed by vector potentials (A, F) over the radiated fields (E & H)?

a) Addition

b) Subtraction

c) Differentiation

d) Integration

 

Q10. Which auxiliary functions assist in solving the radiation problem by evaluation of E & H using sources J & M?

a) Scalar potentials

b) Vector potentials

c) Gradient potentials

d) Divergence potentials

 

Q11. If an observation point is closely located to the source, then the field is termed as ________

a) Induced

b) Radiated

c) Reflected

d) Far-field

 

Q12. Which among the following defines the angular distance between two points on each side of major lobe especially when the radiation drops to zero?

a) Half power beam width (HPBW)

b) First null beam width (FNBW)

c) Side lobe level (SLL)

d) Front to back ratio (FBR) 

 

Q13. At which angles does the front to back ratio specify an antenna gain?

a) 0° & 180°

b) 90° & 180°

c) 180° & 270°

d) 180° & 360°

 

Q14. The knowledge of which parameter is sufficient for deriving the time varying electromagnetic field?

a) Electric field intensity

b) Magnetic field intensity

c) Current density

d) Power density

 

Q15. In a non-isotropic directional antenna, which radiating lobe axis makes an angle of 180° w.r.t. major beam of an antenna?

a) Minor lobe

b) Side lobe

c) Back lobe

d) None of the above

 

Q16. Under which conditions of charge does the radiation occur through wire antenna?

a) For a charge with no motion

b) For a charge moving with uniform velocity with straight & infinite wire

c) For a charge oscillating in time motion

d) All of the above

 

Q17. According to Webster’s dictionary, what is an antenna?

a) Impedance matching device

b) Sensor of electromagnetic waves

c) Transducer between guided wave & free space wavec

d) Metallic device for radiating or receiving radio waves

 

Q18. F2 layer of appleton region acts as a significant reflecting medium for _____ frequency radio waves

a) Low

b) Moderate

c) High

d) All of the above 

 

Q19. Which layer has the atmospheric conditions exactly opposite to that of standard atmosphere?

a) Depression layer

b) Regression layer

c) Inversion layer

d) Invasion layer

 

Q20. On which factor/s do/does the radiation field of a small loop depend?

a) Shape

b) Area

c) Both a and b

d) None of the above 

 

 

Part 4: List for questions and answers of Antenna & wave Propagation

 

Q1. Answer: c

 

Q2. Answer: b

 

Q3. Answer: a

 

Q4. Answer: a

 

Q5. Answer: c

 

Q6. Answer: a

 

Q7. Answer: a

 

Q8. Answer: a

 

Q9. Answer: c

 

Q10. Answer: b

 

Q11. Answer: a

 

Q12. Answer: b

 

Q13. Answer: a

 

Q14. Answer: c

 

Q15. Answer: c

 

Q16. Answer: c

 

Q17. Answer: d

 

Q18. Answer: c

 

Q19. Answer: c

 

Q20. Answer: b