Antenna Arrays - Electronic Engineering (MCQ) questions & answers

1)   If a linear uniform array consists of 9 isotropic elements separated by λ/4, what would be the directivity of a broadside array in dB?

a. 6.53 dB
b. 7.99 dB
c. 8.55 dB
d. 9.02 dB
Answer  Explanation 

ANSWER: 6.53 dB

Explanation:
No explanation is available for this question!


2)   By how many times is an input impedance of a folded dipole at resonance greater than that of an isolated dipole with same length as one of its sides?

a. 2
b. 3
c. 4
d. 6
Answer  Explanation 

ANSWER: 4

Explanation:
No explanation is available for this question!


3)   How do the elements of an active region behave?

a. Inductive
b. Capacitive
c. Resistive
d. None of the above
Answer  Explanation 

ANSWER: Resistive

Explanation:
No explanation is available for this question!


4)   If the length of elements of an array is greater than λ/2, which will be the operating region of an array?

a. Transmission line region
b. Active region
c. Reflective region
d. All of the above
Answer  Explanation 

ANSWER: Reflective region

Explanation:
No explanation is available for this question!


5)   What kind of beamwidth is/are produced by Chebyshev arrays for given side lobe level (SLL)?

a. Widest
b. Narrowest
c. Both a and b
d. None of the above
Answer  Explanation 

ANSWER: Narrowest

Explanation:
No explanation is available for this question!


6)   If the elements of a binomial array are separated by λ/4, how many shape patterns are generated with no minor lobes?

a. 2
b. 4
c. 8
d. 16
Answer  Explanation 

ANSWER: 8

Explanation:
No explanation is available for this question!


7)   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 

ANSWER: α = ±βd

Explanation:
No explanation is available for this question!


8)   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 

ANSWER: Phase

Explanation:
No explanation is available for this question!


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

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

ANSWER: Spherical

Explanation:
No explanation is available for this question!


10)   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 

ANSWER: Conformal

Explanation:
No explanation is available for this question!