Canadian Basic Qualification pool, section B-006-008

Subelement B-006

B-006

Section B-006-008

B-006-008-001

A wire dipole has a resonant frequency of 3900 kHz. How can you change its resonant frequency to 3600 kHz?

A.
Use smaller diameter wire
Correct Answer
B.
Make it longer
C.
Make it shorter
D.
Install it as a sloper

B-006-008-001

Wavelength and frequency have an inverse relationship. Decreasing the resonant frequency (longer wavelength) can be achieved by lengthening the radiating element.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-002

A wire dipole has a resonant frequency of 3600 kHz. How can you change its resonant frequency to 3900 kHz?

Correct Answer
A.
Make it shorter
B.
Make it longer
C.
Install it as a sloper
D.
Use larger diameter wire

B-006-008-002

Wavelength and frequency have an inverse relationship. Increasing the resonant frequency (shorter wavelength) can be achieved by shortening the radiating element.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-003

What is the wavelength in free space of a 25 MHz signal?

A.
39 metres
Correct Answer
B.
12 metres
C.
6 metres
D.
19 metres

B-006-008-003

Wavelength (lambda) in metres IN FREE SPACE is 300 divided by frequency in megahertz. In this example, 300 / 25 = 12 metres.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-004

The velocity of propagation of radio frequency energy in free space is:

A.
200 000 kilometres per second
B.
186 000 kilometres per second
Correct Answer
C.
300 000 kilometres per second
D.
150 000 kilometres per second

B-006-008-004

Radio waves in free space travel at the speed of light: 300 000 kilometres per second.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-005

Adding a series inductance to an antenna would:

A.
increase its useful bandwidth
B.
increase the resonant frequency
C.
reduce atmospheric noise pickup
Correct Answer
D.
decrease the resonant frequency

B-006-008-005

A series inductance in an antenna is termed a "loading coil". It makes the antenna appear LONGER electrically than its physical size. Making the antenna longer brings down the resonant frequency.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-006

The resonant frequency of an antenna may be increased by:

A.
lowering the radiating element
B.
lengthening the radiating element
Correct Answer
C.
shortening the radiating element
D.
increasing the height of the radiating element

B-006-008-006

Wavelength and frequency have an inverse relationship. Increasing the resonant frequency (shorter wavelength) can be achieved by shortening the radiating element.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-007

The speed of a radio wave:

A.
varies depending on the frequency
B.
is constant
C.
is less than half the speed of light
Correct Answer
D.
is the same as the speed of light

B-006-008-007

Radio waves in free space travel at the speed of light: 300 000 kilometres per second.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-008

Why are insulators used at the ends of a suspended wire antenna?

A.
To increase the antenna bandwidth
B.
To decrease the effective antenna length
Correct Answer
C.
To limit the electrical length of the antenna
D.
To reduce capacitive coupling with the ground

B-006-008-008

Insulators mark the end of the antenna. Thus, wet support ropes or metallic support wires do not become part of the antenna.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-009

To lower the resonant frequency of an antenna, the operator should:

A.
lengthen the transmission line
B.
use smaller diameter wire
C.
shorten it
Correct Answer
D.
lengthen it

B-006-008-009

Wavelength and frequency have an inverse relationship. Decreasing the resonant frequency (longer wavelength) can be achieved by lengthening the radiating element.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-010

Some antennas are constructed with traps. What is a trap?

A.
A large wire-wound resistor
B.
A coil wrapped around a ferrite rod
Correct Answer
C.
A coil and capacitor in parallel
D.
A hollow metal can

B-006-008-010

"Antenna traps" are parallel resonant circuits that exhibit high impedance at resonance. Electrically speaking, they cut off the antenna at the trap position when operated at the resonant frequency of the trap.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-006-008-011

What is the wavelength in free space of a 2 MHz signal?

A.
1500 metres
B.
30 metres
C.
360 metres
Correct Answer
D.
150 metres

B-006-008-011

Wavelength (lambda) in metres IN FREE SPACE is 300 divided by frequency in megahertz. In this example, 300 / 2 = 150 metres.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

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