# Antenna Basics-2 MCQ’s

This set of RF & Microwave Circuit Design Multiple Choice Questions & Answers (MCQs) focuses on “Antenna Basics-2″.

1. If an antenna radiates over half a sphere, directivity of the antenna is:
a) Two
b) Four
c) Three
d) One

2. The half power beam width of an antenna in both θ and φ are 400 each. Then the gain of the antenna is:
a) 23
b) 25
c) 14
d) 27

3. As the beam area of an antenna decreases, the directivity of the antenna:
a) Increases
b) Decreases
c) Remains unchanged
d) Depends on the type of the antenna

4. The number N of radio transmitters or point sources of radiation distributed uniformly over the sky which an antenna can resolve is given by:
a) 4π/ ΩA
b) 2π/ ΩA
c) π/ ΩA
d) None of the mentioned

5. Effective aperture is a parameter of the antenna that gives the physical aperture of the antenna.
a) True
b) False

6.________ of an antenna is defined as the ratio of the induced voltage to the incident electric field.
a) Effective height
b) Gain
c) Directivity
d) Loss

7. Ideally, the number of point sources an antenna can resolve is numerically equal to:
a) Gain of the antenna
b) Directivity
c) Beam efficiency
d) Beam area

8. Effective aperture in terms of beam area and operating wavelength is given by the relation:
a) λ2/ ΩA
b) ΩA / λ2
c) λ2× ΩA
d) No such relationship exists

9. The directivity of an antenna in terms of the aperture efficiency and operating wavelength is given by:
a) 4πAe/λ2
b) 2πAe/λ2
c) πAe/λ2
d) None of the mentioned

10. A radio link has 15 W transmitter connected to an antenna of 2.5 m2 effective aperture at 5 GHz. The receiving antenna has an effective aperture of 0.5 m2 and is located at a 15 Km line of sight distance from transmitting antenna. Assuming lossless, matched antennas, the power delivered to the receiver is:
a) 20 µW
b) 15 µm
c) 23 µm
d) 25 µm