Canadian Basic Qualification pool, section B-003-018

Subelement B-003

B-003

Section B-003-018

B-003-018-001

How could you best keep unauthorized persons from using your station at home?

A.
Put a "Danger - High Voltage" sign in the station
Correct Answer
B.
Use a key-operated on/off switch in the main power line
C.
Put fuses in the main power line
D.
Use a carrier-operated relay in the main power line

B-003-018-001

Key word: UNAUTHORIZED. A locked switch in line with the electrical circuit feeding the station would prevent unauthorized operation of the station.

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

Tags: none

B-003-018-002

How could you best keep unauthorized persons from using a mobile station in your car?

Correct Answer
A.
Remove the microphone when you are not using it
B.
Put a "Do not touch" sign on the radio
C.
Turn the radio off when you are not using it
D.
Tune the radio to an unused frequency when you are done using it

B-003-018-002

Key word: UNAUTHORIZED. Locking away or taking away the microphone would prevent unauthorized use of the transmitter.

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

Tags: none

B-003-018-003

What electrical hazard, if any, does the starter battery in a vehicle present?

A.
High electromagnetic fields
Correct Answer
B.
High short-circuit current
C.
None, given its low voltage
D.
Possibility of electric shock

B-003-018-003

While the voltage on the starter battery in a vehicle is low and safe, such batteries can deliver very high currents.

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-003-018-004

Why would there be a switch in a high-voltage power supply to turn off the power if its cabinet is opened?

A.
To keep dangerous RF radiation from leaking out through an open cabinet
Correct Answer
B.
To keep anyone opening the cabinet from getting shocked by dangerous high voltages
C.
To turn the power supply off when it is not being used
D.
To keep dangerous RF radiation from coming in through an open cabinet

B-003-018-004

Key words: HIGH-VOLTAGE. Devices operating with high voltage should always include an 'interlock' switch, so they power down to prevent electrocution when cabinets are opened.

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-003-018-005

What is the minimum electrical current that can be fatal to the human body?

A.
1 ampere
B.
2 amperes
C.
500 milliamperes
Correct Answer
D.
20 milliamperes

B-003-018-005

If the human heart is part of the electrocution path, even one tenth of an ampere can lead to cardiac arrest.

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

Tags: none

B-003-018-006

Which body organ can be fatally affected by a very small amount of electrical current?

Correct Answer
A.
The heart
B.
The liver
C.
The brain
D.
The lungs

B-003-018-006

If the human heart is part of the electrocution path, even one tenth of an ampere can lead to cardiac arrest.

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

Tags: none

B-003-018-007

What is the lowest voltage that is usually considered hazardous to humans?

Correct Answer
A.
30
B.
100
C.
240
D.
347

B-003-018-007

Under certain circumstances, even 30 VOLTS can be dangerous. If the human heart is part of the electrocution path, even one tenth of an ampere can lead to cardiac arrest. Wet skin or cuts to the skin and the exact path of the current are all factors that determine the severity of electrocution.

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

Tags: none

B-003-018-008

What should you do if you discover someone who is being burned by high voltage?

Correct Answer
A.
Turn off the power, call for emergency help and provide first aid if needed
B.
Run from the area so you won't be burned too
C.
Wait for a few minutes to see if the person can get away from the high voltage on their own, then try to help
D.
Immediately drag the person away from the high voltage

B-003-018-008

Step number One: turn off the power. Do not risk electrocuting yourself and become a second victim.

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

Tags: none

B-003-018-009

What is the safest method to remove an unconscious person from contact with a high-voltage source?

A.
Call an electrician
B.
Remove the person by pulling an arm or a leg
Correct Answer
C.
De-energize the power source before touching the person
D.
Wrap the person in a blanket and pull him to a safe area

B-003-018-009

Step number One: turn off the power. Do not risk electrocuting yourself and become a second victim.

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

Tags: none

B-003-018-010

Before checking a fault in a mains-operated power supply unit, it would be safest to first:

A.
short out the leads of the filter capacitor
Correct Answer
B.
turn off the power and unplug the power cord
C.
check the action of the capacitor bleeder resistance
D.
remove and check the fuse from the power supply

B-003-018-010

Key words: "MAINS" OPERATED. This refers to 'Household' current which runs at 120 volts and can supply hundreds of amperes (for a brief time) before a fuse or breaker interrupts the circuit after a fault. 30 VOLTS is considered potentially dangerous to humans and less than A TENTH of an AMPERE can lead to cardiac arrest.

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

Tags: none

B-003-018-011

What is the risk involved in troubleshooting a live power supply?

A.
Electromagnetic interference
B.
Blowing the fuse
Correct Answer
C.
Electric shock
D.
Damaging connected equipment

B-003-018-011

This was especially true of transmitters using vacuum tubes. Plate voltages ran into the hundreds of volts with current capacities of hundreds of milliamperes. 30 VOLTS is considered potentially dangerous to humans and less than A TENTH of an AMPERE can lead to cardiac arrest.

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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