Canadian Basic Qualification pool, section B-004-001

Subelement B-004

B-004

Section B-004-001

B-004-001-001

What term describes a circuit designed to increase the amplitude of a signal?

Correct Answer
A.
Amplifier
B.
Modulator
C.
Multiplier
D.
Oscillator

B-004-001-001

Key word: INCREASE. An amplifier reproduces its input signal into a larger output signal ( more voltage, more current or more power).

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

Tags: none

B-004-001-002

If an amplifier becomes non-linear, the output signal would:

A.
be reduced to zero
B.
overload the power supply
C.
cause oscillations
Correct Answer
D.
become distorted

B-004-001-002

If an amplifier is 'linear', amplification, as a ratio of output versus input, will be constant regardless of frequency or amplitude of the input signal. Linearity is a synonym for 'absence of distortion'. 'Non-linear' implies distortion.

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

Tags: none

B-004-001-003

To increase the level of very weak radio signals from an antenna, you would use:

A.
an audio amplifier
B.
an RF oscillator
C.
an audio oscillator
Correct Answer
D.
an RF amplifier

B-004-001-003

Key words: INCREASE WEAK RADIO signals. A radio frequency (RF) amplifier must be used.

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

Tags: none

B-004-001-004

To increase the level of very weak signals from a microphone you would use:

A.
an RF amplifier
B.
an RF oscillator
Correct Answer
C.
an audio amplifier
D.
an audio oscillator

B-004-001-004

Key words: INCREASE WEAK microphone signal. An 'audio amplifier'. Frequently called a 'speech amplifier' or 'microphone amplifier' for this particular application.

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

Tags: none

B-004-001-005

What range of frequencies does the speech amplifier of an amateur radio transceiver typically process?

A.
40 Hz to 40 000 Hz
B.
3 Hz to 300 Hz
C.
300 Hz to 1 000 Hz
Correct Answer
D.
300 Hz to 3 000 Hz

B-004-001-005

Frequencies audible to humans range from 20 Hz to 20 000 Hz. Speech frequencies important for intelligibility in communications range from 300 Hz to 3000 Hz.

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

Tags: none

B-004-001-006

Apart from power and current, which signal property can amplifiers be specifically designed to increase?

Correct Answer
A.
Voltage
B.
Linearity
C.
Frequency
D.
Phase

B-004-001-006

Amplifiers work on voltage, current and power.

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

Tags: none

B-004-001-007

The increase in signal level by an amplifier is called:

A.
attenuation
B.
modulation
Correct Answer
C.
gain
D.
amplitude

B-004-001-007

Gain (synonymous with amplification) is an increase in signal voltage/current/power. 'Attenuation' is a loss (opposite to gain). 'Amplitude' is the instantaneous value of a signal. 'Modulation' is the impression of a message onto another signal.

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

Tags: none

B-004-001-008

A device with gain has the property of:

A.
attenuation
B.
oscillation
C.
modulation
Correct Answer
D.
amplification

B-004-001-008

Gain and Amplification are synonymous. 'Attenuation' is a loss (opposite to gain). 'Oscillation' is the production of an Alternating Current (AC) signal. 'Modulation' is the impression of a message onto another signal.

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

Tags: none

B-004-001-009

A device labelled "Gain = 10 dB" is likely to be an:

A.
audio fader
B.
attenuator
C.
oscillator
Correct Answer
D.
amplifier

B-004-001-009

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

Tags: none

B-004-001-010

What term describes the ratio of output power to DC input power of an amplifier?

A.
Dynamic range
Correct Answer
B.
Efficiency
C.
Current gain
D.
Loss factor

B-004-001-010

Efficiency compares the output power and the input power of a device. If there were no losses, they would be identical. In real life, every device wastes some of the input power as heat and the output power is lower. For example, a transmitter consumes 150 watts of direct current to produce 90 watts of RF, its efficiency is 60% (90 / 150).

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

Tags: none

B-004-001-011

What is the result of excessive positive feedback in an amplifier stage?

A.
Frequency response is flattened
B.
Distortion is minimized
Correct Answer
C.
Oscillations appear
D.
Voltage gain is reduced

B-004-001-011

For an oscillation to be produced in a circuit, gain (an amplifier) is required and a feedback with the correct phase from output to input must be present. If positive feedback appears in an amplifier, it becomes an oscillator.

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

Tags: none

Log in

- or -

- or -