Deck 14: Antennas

Question 1

For frequencies below 2 MHz, which antenna is used?

A) Helmhotz
B) vertical
C) Hertz
D) dipole

Answer 1

B

Question 2

It is desired to build a dipole to receive a 49 MHz broadcast. The optimum length for the dipole antenna is:

A) 2.91 meters.
B) 6.12 meters.
C) 3.06 meters.
D) 5.82 meters.

Answer 2

D

Question 3

The half-wave dipole antenna has gain relative to an isotropic radiator of

A) 1.67dB
B) 3 dB
C) 5 dB
D) 2.15 dB

Answer 3

D

Question 4

Antenna gain provided with respect to an isotropic radiator is expressed as:

A) dBi
B) dBW
C) dBV
D) dBm

Question 5

The characteristic impedance of twin lead is(in ohms):

A) 150
B) 600
C) 75
D) 300

Question 6

Which of the following antennas matches well with the 300- Ohm input impedance terminals?

A) folded dipole antenna
B) loop antenna
C) slot antenna
D) ferrite loop antenna

Question 7

Which of the following is a directional antenna?

A) dipole
B) vertical
C) Yagi-Uda
D) all of the above

Question 8

A series inductance used to tone out the capacitive appearance of an antenna is called

A) wading coil
B) Condenser
C) RF choke
D) pole

Question 9

An antenna created by taking a quarter-wavelength section of open wire line and bending each conductor outward 90 degrees is called:

A) a Marconi antenna.
B) a vertical antenna.
C) a dipole antenna.
D) all of the above.

Question 10

A group of antennas or antenna elements arranged to provide the desired directional characteristics is called:

A) an antenna array
B) a vertical antenna
C) a lumped element
D) a marconi antenna

Question 11

The adjustment of the single stub tuner in the Electronics Workbench Multisim simulation was accomplished by changing the effective length of the :

A) top leg
B) ground leg
C) right leg
D) long leg

Question 12

Any non-driven element of an antenna array such as a Yagi is called a:

A) parasitic element.
B) reflector
C) director
D) lobe

Question 13

A direction in space with minimal signal level is called a:

A) slip
B) null
C) space
D) mark

Question 14

An impedance matching device that spreads the transmission line as it approaches the antenna is called a:

A) flared match
B) series match
C) wave match
D) delta match

Question 15

The model of the dipole antenna used in the Electronics Workbench Multisim simulation used an inductance of 1 H and series capacitor of 2.5pF. The resonant frequency of this antenna model is approximately:

A) 103.9 MHz
B) 110 MHz
C) 90 MHz
D) 100 MHz

Question 16

Feeling the half-wave dipole (Hertz) antenna at the center results in an input impedance that is purely resistive and equal to:

A) 58
B) 300
C) 50
D) 73

Question 17

The antenna gain, given in decibel with respect to a dipole is expressed as:

A) dBd
B) dBW
C) dBV
D) dBi

Question 18

Which of the following is used to determine antenna bandwidth?

A) power
B) center frequency
C) wavelength
D) all of the above