Unit D Section 1.3

Question 1

What is a short circuit?

Answer 1

A short circuit is any bypass in normal circuit or unintended pathway or breakage in a circuit.

Question 2

Why is a short circuit dangerous?

Answer 2

It is dangerous because, without a complete circuit, electricity can’t flow. However, electricity can go through another path such as the human body.

Question 3

Two important aspects of electricity:

Answer 3

Voltage

Amperage

Question 4

Which is more important voltage or amperage?

Answer 4

The number of amps is much more important than voltage when assessing the potential danger of an electrical shock
Ex: 0.1 A is enough to be fatal

Question 5

How are you safe from a short circuit in a car?

Answer 5

A downed power line is touching the truck, but the driver is not electrocuted as long as he stays in the truck. If he must leave, he should jump free, not step out. Stepping to the ground would provide a path for the electricity to flow through him to the ground.

Question 6

Factors affecting Electrical Shock:

Answer 6

How easily the current flows. (Conductors/Insulator)
If there is a short circuit.
The weather ( dry weather is better than wet)

Question 7

Electrical Safety Pointers:

Answer 7

• Never handle electrical devices when you are wet or near water unless they are specially designed
• Don’t use any power cord that is frayed or broken.
• Always unplug electrical devices before looking inside or servicing them.
• Don’t put anything into an electrical outlet other than proper plugs for electrical devices
• Don’t overload circuits by plugging in and operating too many devices.
• Stay away from power lines.
• Don’t bypass safety features built into home wiring, appliances, and other electrical devices
• When unplugging a device, pull on the plug, not on the electrical cord.
• Never remove the third prong from a three-prong plug.

Question 8

The purpose of a three-prong plug:

Answer 8

A three-prong plug has an extra wire that connects the device to the ground wire of the building. It provides another pathway for electricity, just in case there is a short circuit in the device.

Question 9

What are fuses and circuit breakers?

Answer 9

They interrupt a circuit when too much current is flowing through it.

Question 10

Fuses

Answer 10

. Fuses contain a thin piece of metal that melts that to much current passes through. nichrome and tungsten wires are uses as fuse - they melt and disconnect the appliances

Question 11

circuit breakers

Answer 11

Most household circuit breakers also have a special wire that heats up if there is too much current

In a circuit breaker, the wire triggers a spring mechanism that turns off the switch inside. Don’t turn it one until the problem is fixed.

Question 12

How much electricity can Lightning have?

And where does it strike the most?

Answer 12

Lightning can have as much as 30 000 A

Lightning is a huge amount of negative charge and tends to seek the highest point on the horizon to discharge.

Question 13

People who are struck by lightning:

Answer 13

People who are struck by lightning suffer sever injuries.

Question 14

How are lightnings prevented from striking buildings?

Answer 14

Lightning rods are connected to the ground with a wire. Instead of the lightning destroying the building’s roof, lightning hits the ground.