Antenna & Wave Propagation Test Questions Set 1

1)   What is the wavelength of Super high frequency (SHF) especially used in Radar & satellite communication?

a. 1 m – 10 m
b. 1 cm – 10 cm
c. 10 cm – 1 m
d. 0.1 cm – 1 cm
Answer  Explanation  Related Ques

ANSWER: 1 cm – 10 cm

Explanation:
No explanation is available for this question!


2)   Which among the following is an application of high frequency?

a. SONAR
b. Subsurface communication
c. Radio navigation
d. Facsimile
Answer  Explanation  Related Ques

ANSWER: Facsimile

Explanation:
No explanation is available for this question!


3)   Wavefront is basically a locus of points acquiring similar _______

a. Phase
b. Frequency
c. Amplitude
d. Wave equation
Answer  Explanation  Related Ques

ANSWER: Phase

Explanation:
No explanation is available for this question!


4)   In which kind of waveform is the phase velocity defined?

a. Sinusoidal
b. Rectangular
c. Square
d. Triangular
Answer  Explanation  Related Ques

ANSWER: Sinusoidal

Explanation:
No explanation is available for this question!


5)   Which among the following is/are not present in free space?

a. Solid bodies
b. Ionized particles
c. Interference of normal radiation & radio wave propagation
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


6)   Power density is basically termed as ________ power per unit area

a. Reflected
b. Refracted
c. Radiated
d. Diffracted
Answer  Explanation  Related Ques

ANSWER: Radiated

Explanation:
No explanation is available for this question!


7)   If the path difference of two waves with single source traveling by different paths to arrive at the same point, is λ/2, what would be the phase difference between them?

a. β x (λ/2)
b. β / (λ/2)
c. β + (λ/2)
d. β - (λ/2)
Answer  Explanation  Related Ques

ANSWER: β x (λ/2)

Explanation:
No explanation is available for this question!


8)   Which ionization layer exists during day time & usually vanishes at night due to highest recombination rate?

a. D-region
b. Normal E-region
c. Sporadic E-region
d. Appleton region
Answer  Explanation  Related Ques

ANSWER: D-region

Explanation:
No explanation is available for this question!


9)   What is the possible range of height for the occurrence of sporadic E-region with respect to normal E-region?

a. 20 km – 50 km
b. 45 km – 85 km
c. 90 km – 130 km
d. 140 km – 200 km
Answer  Explanation  Related Ques

ANSWER: 90 km – 130 km

Explanation:
No explanation is available for this question!


10)   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
Answer  Explanation  Related Ques

ANSWER: High

Explanation:
No explanation is available for this question!


11)   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
Answer  Explanation  Related Ques

ANSWER: Current density

Explanation:
No explanation is available for this question!


12)   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 wave
d. Metallic device for radiating or receiving radio waves
Answer  Explanation  Related Ques

ANSWER: Metallic device for radiating or receiving radio waves

Explanation:
No explanation is available for this question!


13)   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
Answer  Explanation  Related Ques

ANSWER: For a charge oscillating in time motion

Explanation:
No explanation is available for this question!


14)   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
Answer  Explanation  Related Ques

ANSWER: Back lobe

Explanation:
No explanation is available for this question!


15)   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°
Answer  Explanation  Related Ques

ANSWER: 0° & 180°

Explanation:
No explanation is available for this question!


16)   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)
Answer  Explanation  Related Ques

ANSWER: First null beam width (FNBW)

Explanation:
No explanation is available for this question!


17)   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
Answer  Explanation  Related Ques

ANSWER: Induced

Explanation:
No explanation is available for this question!


18)   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
Answer  Explanation  Related Ques

ANSWER: Vector potentials

Explanation:
No explanation is available for this question!


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

a. Addition
b. Subtraction
c. Differentiation
d. Integration
Answer  Explanation  Related Ques

ANSWER: Differentiation

Explanation:
No explanation is available for this question!


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

a. Current
b. Voltage
c. Frequency
d. Phase
Answer  Explanation  Related Ques

ANSWER: Current

Explanation:
No explanation is available for this question!


21)   How are the infinitesimal dipoles represented in terms of antenna length and signal wavelength?

a. l ≤ (λ /50)
b. (λ/50 ) < l ≤ (λ /10)
c. l = λ/2
d. None of the above
Answer  Explanation  Related Ques

ANSWER: l ≤ (λ /50)

Explanation:
No explanation is available for this question!


22)   In flared transmission line, the radiation phenomenon increases due to ________ in flaring

a. Increase
b. Decrease
c. Stability
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Increase

Explanation:
No explanation is available for this question!


23)   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
Answer  Explanation  Related Ques

ANSWER: Power Pattern

Explanation:
No explanation is available for this question!


24)   In an 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
Answer  Explanation  Related Ques

ANSWER: Less than

Explanation:
No explanation is available for this question!


25)   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
Answer  Explanation  Related Ques

ANSWER: Area

Explanation:
No explanation is available for this question!


26)   From the radiation point of view, small loops are _________radiators

a. Poor
b. Good
c. Better
d. Excellent
Answer  Explanation  Related Ques

ANSWER: Poor

Explanation:
No explanation is available for this question!


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

a.
b. 90°
c. 180°
d. 270°
Answer  Explanation  Related Ques

ANSWER: 90°

Explanation:
No explanation is available for this question!


28)   In which kind of array configuration, the element locations must deviate or adjust to some nonplaner surface like an aircraft or missile?

a. Linear
b. Planer
c. Conformal
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Conformal

Explanation:
No explanation is available for this question!


29)   What is the nature of radiation pattern of an isotropic antenna?

a. Spherical
b. Dough-nut
c. Elliptical
d. Hyperbolic
Answer  Explanation  Related Ques

ANSWER: Spherical

Explanation:
No explanation is available for this question!


30)   In broadside array, all the elements in the array should have similar _______excitation along with similar amplitude excitation for maximum radiation.

a. Phase
b. Frequency
c. Current
d. Voltage
Answer  Explanation  Related Ques

ANSWER: Phase

Explanation:
No explanation is available for this question!


31)   Which among the following is regarded as a condition of an ordinary endfire array?

a. α < βd
b. α > βd
c. α = ±βd
d. α ≠ ±βd
Answer  Explanation  Related Ques

ANSWER: α = ±βd

Explanation:
No explanation is available for this question!


32)   Which mode of propagation is adopted in HF antennas?

a. Ionospheric
b. Ground wave
c. Tropospheric
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Ionospheric

Explanation:
No explanation is available for this question!


33)   For which band/s is the space wave propagation suitable over 30 MHz?

a. VHF
b. SHF
c. UHF
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


34)   If the tower antenna is not grounded, which method of excitation is/are applicable for it?

a. Series
b. Shunt
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Series

Explanation:
No explanation is available for this question!


35)   In ungrounded antennas, if an excitation is applied directly across the base insulator, then on which factor/s would the voltage across the insulator depend?

a. Power delivered to antenna
b. Power factor of impedance
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!