Antenna & Wave Propagation Test Questions - Set 2

1)   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 

ANSWER: Metallic device for radiating or receiving radio waves

Explanation:
No explanation is available for this question!


2)   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 

ANSWER: For a charge oscillating in time motion

Explanation:
No explanation is available for this question!


3)   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 

ANSWER: Back lobe

Explanation:
No explanation is available for this question!


4)   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 

ANSWER: 0° & 180°

Explanation:
No explanation is available for this question!


5)   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 

ANSWER: First null beam width (FNBW)

Explanation:
No explanation is available for this question!


6)   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 

ANSWER: Induced

Explanation:
No explanation is available for this question!


7)   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 

ANSWER: Current

Explanation:
No explanation is available for this question!


8)   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 

ANSWER: l ≤ (λ /50)

Explanation:
No explanation is available for this question!


9)   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 

ANSWER: Increase

Explanation:
No explanation is available for this question!


10)   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 

ANSWER: Power Pattern

Explanation:
No explanation is available for this question!