ESD and Electrical Devices Flashcard

Front

Which of the following devices can store large amounts of electricity, even when unplugged? CRT monitor, DVD optical drive, Hard disk drive, LCD monitor

Back

CRT monitor

Answer explanation

A cathode ray tube (CRT) monitor can store large amounts of electricity, even when unplugged.

You should never open a CRT monitor, as the capacitors within the CRT can store enough electricity to be lethal.

LCD monitors do not use large capacitors and are much safer to work on than CRT monitors (although the CCFL backlight has mercury vapor in it, which could be harmful if the tube is broken).

DVD optical drives and hard disk drives do not store electricity in sufficient quantity to be harmful.

Front

What is the minimum ESD volt discharge that can actually damage a component?

Back

100 volts

Answer explanation

The minimum ESD voltage that can damage components is typically around 100 volts. Voltages below this threshold are less likely to cause harm, while 100 volts and above can lead to potential damage.

A discharge of as little as 100 volts, or less, can damage a component, but 3,000 volts or more of ESD must occur before you can even feel it.

Front

Which of the following would BEST protect you from static electricity buildup while repairing computers in a carpeted room? ESD mat, ESD wrist strap, Self-grounding, ESD heel strap

Back

ESD wrist strap

Answer explanation

An ESD wrist strap is designed to safely ground static electricity from your body to prevent buildup, making it the best choice for protection against static electricity compared to the other options.

EXPLANATION: Walking across a room, especially on carpet, will generate static electricity on your person. Discharging this electricity to a computer component may damage that component. Under these circumstances, it is best to use an electrostatic discharge (ESD) wrist strap to ensure proper grounding.An ESD heel strap only works if the surface the technician is walking on is ESD-protected. Since this room has nothing but carpet, heel straps would be ineffective.  ESD mats neutralize the static buildup between the computer and mat, but it is still best if you connect yourself to the computer via an ESD wrist strap. Otherwise, the static electricity you gain by walking across the floor can still be discharged to a computer component you touch. Although self-grounding is good, the fact that you are working on carpet means that additional static may build up if you shuffle your feet while working.

Front

Hard drives are best stored in which of the following? Static shielding bag, Refrigerator, Styrofoam-lined box, Plastic bag

Back

Static shielding bag

Answer explanation

Hard drives are best stored in a static shielding bag as it protects them from electrostatic discharge, which can damage the sensitive components.

Other options do not provide adequate protection.

Styrofoam should not be used with computer components, as it is a vigorous source of ESD. Other types of foam might protect components from damage during shipment, but do not protect equipment from ESD.

Storing a hard drive in the refrigerator does little to protect the drive from damage, and can be contaminated from other items in the refrigerator.

Storing a plastic bag does little to protect the hard drive and can introduce ESD that will damage the hard drive.

Front

ESD is most likely to occur in which of the following environments? In a cool, humid atmosphere, In a cool, dry atmosphere, In a warm, humid atmosphere, In a warm, dry atmosphere

Back

In a warm, dry atmosphere

Answer explanation

ESD (Electrostatic Discharge) is most likely to occur in a warm, dry atmosphere because low humidity reduces the conductivity of air, allowing static charges to build up more easily.

Front

To ensure your personal safety, which of the following should you do FIRST when upgrading a video card?
Options:
Place the computer on an ESD mat.
Put on safety glasses.
Remove jewelry.
Disconnect power.

Back

Disconnect power.

Answer explanation

Before you begin any internal service on a computer, you must always be sure that the computer is completely disconnected from the power source. Not removing power can lead to serious harm or death.

After the power is disconnected, you should remove any jewelry. Doing this eliminates the possibility of accidentally getting any electronic discharges.

Placing the computer on an ESD mat and using safety glasses would also be beneficial, but the first thing you should do is disconnect power.

Front

What should be your top priority when responding to emergencies and hazardous situations?

Back

Ensure the safety of people in the area.

Answer explanation

In emergencies, the top priority must be to ensure the safety of people in the area. Protecting lives is paramount, as no data or equipment is worth more than human safety.

Front

As you are setting up the employees' desktop computers, you come to one location where the nearest wall outlet has only two prongs. All of the metal-enclosed desktop computers have three-prong cords. Which of the following is the BEST way to proceed with that particular desktop computer? Purchase an adapter that converts the three-prong cable to two prongs. Get a new power cord with two prongs to match the wall outlet. Use the existing cord, but remove the grounding prong, as it is not required. Find a different outlet that uses three prongs.

Back

Find a different outlet that uses three prongs.

Answer explanation

The third, or middle, prong of a computer plug is the grounding prong. In the event of a malfunction, the electricity flows through the grounding prong to the earth which, in turn, trips off the breaker, removing all electricity from that outlet.

If the grounding prong is removed or bypassed and a malfunction occurs, the electricity will find the next shortest path to the earth, which may be a person who touches the computer. Having the electricity pass through a person could cause serious harm or even death.

You should never remove the third grounding prong or use an adapter to bypass the prong.

Front

Of the following choices, which action could cause the MOST permanent physical harm to you?
- Looking into the end of a fiber optic cable.
- Wearing a grounding strap while installing a modem.
- Using a computer without a surge protector.
- Force-ejecting a stuck DVD disc using a straightened paper clip.

Back

Looking into the end of a fiber optic cable.

Answer explanation

Looking into the end of a fiber optic cable can cause serious eye damage due to the intense light transmitted through it, making it the action that could cause the most permanent physical harm.

Front

Which of the following is a myth regarding electrostatic discharge (ESD)?
Options:
Sitting down or standing up from a chair can create static electricity.
If you can't feel ESD, the surge is not sufficient to harm computer components.
Most often, ESD degrades computer components, and they fail at a later date.
Simply touching an object can create static electricity. You do not have to rub the object.

Back

If you can't feel ESD, the surge is not sufficient to harm computer components.

Answer explanation

The statement 'If you can't feel ESD, the surge is not sufficient to harm computer components' is a myth.

ESD can damage components even if the discharge is not felt.

The other answers are true:
Sitting down or standing up from a chair can create static electricity. (True)

Most often, ESD degrades computer components, and they fail at a later date. (True)

Simply touching an object can create static electricity. You do not have to rub the object. (True)