The basic requirements of transmitting antennas are:
A. High efficiency
B. Low side lobes
C. Large signal to noise ratio
D. None of the mentioned
Answer: A
Which one of the devices converts electrons to photons or vice-versa.
A. Antenna
B. Electron gun
C. Photon amplifier
D. Microwave tube
Answer: A
The basic equation of radiation that is applied to any antenna irrespective of the type of the antenna
is:
A. iL= Qv
B. iQ = Lv
C. i/L=Q/v
D. None of the mentioned
Answer: A
The number of patterns radiation pattern required to specify the characteristic are
A. Three
B. Four
C. Two
D. Five
Answer: A
The beam width of the antenna pattern measured at half power points is called:
A. Half power beam width
B. Full null beam width
C. Beam width
D. None of the mentioned
Answer: A
An antenna has a field pattern of E (θ) = cos2 θ, θ varies between 0 and 900. Half power beam
width of the antenna is:
A. 330
B. 660
C. 1200
D. None of the mentioned
Answer: B
An antenna has a field pattern E (θ) =cos θ. cos 2θ. The first null beam width of the antenna is:
A. 450
B. 900
C. 1800
Answer: B
The solid area through which all the power radiated by the antenna is:
A. Beam area
B. Effective area
C. Aperture area
D. Beam efficiency
Answer: A
Power radiated from an antenna per unit solid angle is called radiation intensity.
A. True
B. False
Answer: A
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
Answer: A
If an antenna radiates over half a sphere, directivity of the antenna is:
A. Two
B. Four
C. Three
D. One
Answer: A
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
Answer: B
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
Answer: A
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
Answer: B
Effective aperture is a parameter of the antenna that gives the physical aperture of the antenna.
A. True
B. False
Answer: B
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
Answer: A
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
Answer: A
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
Answer: A
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
Answer: C
The members of the antenna family which are made of wires of certain value in terms of operating
wavelength are called:
A. Loop antennas
B. Wire antennas
C. Dipole antenna
D. Slot antennas
Answer: C
