# Antenna Theory & Wave Propagation- Online Test 4

15 Questions | Total Attempts: 860  Settings  The quiz below is the fourth and final one in a series of tests aimed at testing out how much you understand on antenna theory and wave propagation. Give it a try and do come back for more quizzes to help you in your end year applied physics exams.

• 1.
What is the radiation characteristic of a dipole antenna?
• A.

Omnidirectional

• B.

Bidirectional

• C.

Unidirectional

• D.

Hemispherical

• 2.
An antenna with unity gain
• A.

Rhombic

• B.

Half-wave dipole

• C.

Isotropic

• D.

Whip

• 3.
What is the theoretical gain of a Hertzian dipole?
• A.

1.76 dB

• B.

2.15 dB

• C.

3 dB

• D.

0 dB

• 4.
How will you increase the gain of an antenna?
• A.

By adding several antennas in parallel

• B.

By adding several antennas in parallel

• C.

By making antenna rods thicker

• D.

By making the antenna size larger

• 5.
An antenna which is one-tenth wavelength long
• A.

Hertzian dipole

• B.

Loop antenna

• C.

Marconi antenna

• D.

Elementary doublet

• 6.
What is the minimum number of turns a helix antenna must have?
• A.

3

• B.

5

• C.

4

• D.

6

• 7.
What is the gain of isotropic antenna?
• A.

10

• B.

1

• C.

100

• D.

1000

• 8.
The length of a Marconi antenna to operate with 985 kHz is ______.
• A.

200 ft

• B.

500 ft

• C.

250 ft

• D.

999 ft

• 9.
What is the front-to-back ratio of an antenna which radiates 500 watts in a north direction and 50 watts in south direction?
• A.

25000 dB

• B.

10 dB

• C.

100 dB

• D.

20 dB

• 10.
Which of the following improves antenna directivity?
• A.

Driven element

• B.

Reflector element

• C.

Director element

• D.

Parasitic element

• 11.
The antenna radiates _____ polarized waves when the transmitter antenna is horizontally installed.
• A.

Vertically

• B.

Negatively

• C.

Horizontally

• D.

Circularly

• 12.
. If 4 kW in antenna produces 50 μV/m in a receiving antenna, a 15 kW will produce _____.
• A.

200 μV/m

• B.

10 μV/m

• C.

100 μV/m

• D.

20 μV/m

• 13.
If the radiated power increase 10.89 times, the antenna current increases by ______.
• A.

3.3 times

• B.

6.6 times

• C.

1.82 times

• D.

10.89 times

• 14.
The frequency of operation of a dipole antenna cut to a length of 3.4 m.
• A.

88 MHz

• B.

44 MHz

• C.

22 MHz

• D.

11 MHz

• 15.
Comparing the signal strength arriving at the driven element from the desired direction to the signal strength reaching the driver from the opposite direction.
• A.

Directivity

• B.

Sensitivity

• C.

Beamwidth

• D.

Front-to-back ratio

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