Canadian Basic Qualification pool, section B-004-002

Subelement B-004

B-004

Section B-004-002

B-004-002-001

A diode is in series in the positive power lead to a transceiver. What is its purpose?

A.
Protect against voltage transients
B.
Overcurrent protection
Correct Answer
C.
Reverse polarity protection
D.
Permit AC operation

B-004-002-001

The ability of diodes to conduct in one direction only makes them suitable to protect equipment against incorrect polarity at the DC input.

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

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B-004-002-002

One important application for diodes is recovering information from transmitted signals. This is referred to as:

A.
conversion
B.
regeneration
Correct Answer
C.
detection
D.
biasing

B-004-002-002

Detection = DEmodulation = Recovery of the message carried on a radio signal.

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

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B-004-002-003

The primary purpose of a Zener diode is to:

Correct Answer
A.
regulate or maintain a constant voltage
B.
boost the power supply voltage
C.
provide a path through which current can flow
D.
provide a voltage phase shift

B-004-002-003

ZENER diodes maintain a constant voltage across their terminals. Hence, they are used for voltage regulation.

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

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B-004-002-004

The action of changing alternating current to direct current is called:

A.
transformation
B.
amplification
Correct Answer
C.
rectification
D.
modulation

B-004-002-004

Changing AC to DC is called 'Rectification'. AC is turned into 'pulsating DC' (it flows in one direction only) after going through a diode. In Power Supply circuits, diodes are called 'Rectifiers'. Diodes have two electrodes: Cathode and Anode. Electrons flow from Cathode to Anode in a forward-biased (i.e., a diode subjected to a voltage polarity that permits conduction) diode.

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

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B-004-002-005

The electrodes of a semiconductor diode are known as:

A.
collector and base
B.
gate and source
C.
cathode and drain
Correct Answer
D.
anode and cathode

B-004-002-005

A DIODE, vacuum tube or semiconductor, has two electrodes: Anode and Cathode. Electrons flow from Cathode to Anode in a forward-biased (i.e., a diode subjected to a voltage polarity that permits conduction) diode. Cathode / Grid / Anode (plate) are electrodes in a vacuum triode. Source / Gate / Drain are electrodes in a Field Effect Transistor (FET, N-Channel or P-Channel). Emitter / Base / Collector are electrodes in a Bipolar Transistor ( type PNP or NPN ).

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

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B-004-002-006

If alternating current is applied to the anode of a diode, what would you expect to see at the cathode?

A.
No signal
Correct Answer
B.
Pulsating direct current
C.
Pulsating alternating current
D.
Steady direct current

B-004-002-006

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

Tags: none

B-004-002-007

In a semiconductor diode, electrons flow from:

A.
anode to cathode
B.
base to collector
C.
source to drain
Correct Answer
D.
cathode to anode

B-004-002-007

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

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B-004-002-008

What semiconductor device glows different colours, depending upon its chemical composition?

A.
A neon bulb
Correct Answer
B.
A light-emitting diode
C.
A vacuum diode
D.
A fluorescent bulb

B-004-002-008

Key word: SEMICONDUCTOR. "LED", a Light-Emitting Diode.

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

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B-004-002-009

Which property of a semiconductor diode permits its use for reverse-polarity protection?

A.
It has high forward resistance
Correct Answer
B.
It conducts in one direction only
C.
Its peak inverse voltage is below 1 volt
D.
It has a high response speed

B-004-002-009

The ability of diodes to conduct in one direction only makes them suitable to protect equipment against incorrect polarity at the DC input.

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

Tags: none

B-004-002-010

In order for a diode to conduct, it must be:

Correct Answer
A.
forward biased
B.
reverse biased
C.
enhanced
D.
close coupled

B-004-002-010

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

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