Student safety 2011 5th edition - Pt 1 , Pg 1-5

Question 1

What does “energized” mean in electricity?

Pg 2

Answer 1

electrically connected to/have voltage source

Question 2

What does “exposed” mean in electricity?

Pg 2

Answer 2

(applied to energized electrical conductors) can be inadvertently touched nearer than a safe distance by a person.

Question 3

What does “externally operable” mean in electricity?

Pg 2

Answer 3

capable to be operated without exposing the operator to contact with energized electrical conductors or circuit parts

Question 4

What does “in operation” mean in electricity?

Pg 2

Answer 4

a term to describe a lab

A lab is in operation if it meet these conditions:

• power is on in a workstation
• students are wiring/troubleshooting equipment/circuits/staff are setting up or troubleshooting equipment or circuits

Question 5

What’s a safety eyewear?

Pg 2

Answer 5

safety glasses meeting current standards for low impact eye
protection, which must have side shields

Question 6

What’s a safety footwear?

Pg 2

Answer 6

any CSA approved footwear bearing the green triangle

Question 7

What’s a circuit?

Pg 2

Answer 7

E.g. A path that can result with a turned on flashlight’s batteries has electricity flow to the lamp and back to it.

Question 8

What’s the amount of electricity flowing called?

Pg 3

Answer 8

current

Question 9

What’s the amount of electricity flowing in a circuit measured in?

Pg 3

Answer 9

amps

Question 10

Current flows in a circuit due to the voltage supplied by what?

Pg 3

Answer 10

power source (battery, power supply)

Question 11

If a circuit’s voltage increases the current also…?.

Pg 3

Answer 11

…increase

Question 12

Circuits that are connected to a voltage source are
described as what?

Pg 3

Answer 12

alive/live

Question 13

If you become part of a circuit, current gets through and you get _______.

Pg 3

Answer 13

If you become part of a circuit, current gets through and you get shocked.

Question 14

When you become part of a circuit means you are connected it circuit in _ different places.

Pg 3

Answer 14

When you become part of a circuit means you are connected it circuit in 2 different places.

Question 15

What’s does the “ground” refers to in electricity?

Pg 3

Answer 15

The “ground”
refers to the planet and any metal connected to it.

Question 16

Plumbing pipes, heating ducts and metal building structures are all ________.

Pg 3

Answer 16

Plumbing pipes, heating ducts and metal building structures are all grounded.

Question 17

Touching that’s grounded and a part of the circuit that is live to ground will result in what?

Pg 3

Answer 17

Touching that’s grounded and a part of the circuit that is live to ground will result in a shock.

Question 18

What’s a main factor to determine a shock’s severity?

Pg 3

Answer 18

the amount of current

Question 19

Shock currents are often measured in what?

Pg 3

Answer 19

in milliamps (mA)

Question 20

a milliamp is ________ (1/_) of an amp?

Pg 3

Answer 20

a milliamp is thousand (1/1000) of an amp

Question 21

What does proportional mean?

Pg 3

Answer 21

corresponding

Question 22

True or false?
Current is not proportional to voltage

Pg 3

Answer 22

false
Since current is proportional to voltage, higher voltages lead to worse shocks

Question 23

What’s the lowest distribution voltage that utilities use?

Pg 4

Answer 23

2,400-9,000 volts

Question 24

Is the lowest distribution voltage that utilities use life threatening?

Pg 4

Answer 24

Yes, at
this voltage any direct contact is life threatening.

Question 25

Pure water is a ____ conductor of electricity. Most water, including in the body, has dissolved ions that make us better conductors. ## Footnote Pg 4

Answer 25

Pure water is a **poor** conductor of electricity. Most water, including in the body, has dissolved ions that make us better conductors.

Question 26

True or false? Dry skin has relatively high resistance against current. ## Footnote Pg 4

Answer 26

true

Question 27

Despite a skin's high resistance, what's beneath can still make us a good electricity conductor? ## Footnote Pg 4

Answer 27

Our skin's tissue beneath is mostly water. Even a tiny break in the skin creates a low resistance path makes a shock worse.

Question 28

True or false? It's safe to wear metal wristband and Why? ## Footnote Pg 4

Answer 28

false A metal wristband makes a big contact area and makes a shock worse.

Question 29

What can the skin's initial burning and blistering lower resistance cause? ## Footnote Pg 4

Answer 29

It cause more intense shock, burning, and blistering.

Question 30

True or false? Even a tiny current through the chest affect breathing or a heart to beat. Current through the brain can be fatal. ## Footnote Pg 4

Answer 30

true

Question 31

True or false? Up to 1 mA we can feel a shock. ## Footnote Pg 4

Answer 31

false Up to 1 mA we usually **can't** feel a shock.

Question 32

True or false? At ~8 mA people feel a shock without injury. ## Footnote Pg 4

Answer 32

true

Question 33

What does GFCI stand for? ## Footnote Pg 4

Answer 33

Ground Fault Circuit Interrupters

Question 34

What's GFCI used for and it's opened at how much mA? ## Footnote Pg 4

Answer 34

GFCIs can protect others in high risk areas like bathrooms, opened at 5 mA.

Question 35

Currents above what mA cause burns? ## Footnote Pg 5

Answer 35

Currents +**100 mA** cause burns. | Most source states 100 mA, but the Student Safety book states 10 mA.

Question 36

True or false? ~10-20 mA **won't** include 1st and 2nd degree burns. ## Footnote Pg 5

Answer 36

false ~10-20 mA include 1st and 2nd degree burns.

Question 37

What can above 10-20 mA cause to the body? ## Footnote Pg 5

Answer 37

What can above 10-20 mA cause to the body?

Question 38

Why can't we let go of what's electrocuting us? ## Footnote Pg 5

Answer 38

**loss of muscle control** A shock's current may cause muscle to contract and "freeze”, one cannot let go even at will.

Question 39

What's the max current an average person can grasp and “let go” ## Footnote Pg 5

Answer 39

Average people can grasp and “let go” at a max of **16** mA. ## Footnote https://www.ccohs.ca/oshanswers/safety_haz/welding/electric.html#section-2-hdr

Question 40

What can 20 mA do to muscles? ## Footnote Pg 5

Answer 40

20 mA may cause muscles for breathing to be **paralysed**.

Question 41

What happens to a body at 100 mA? ## Footnote Pg 5

Answer 41

At 100 mA **ventricular fibrillation** occurs--heart **stops pumping**.

Question 42

What happens to a body at 200 mA? ## Footnote Pg 5

Answer 42

Over 200 mA the heart muscles clamp. There is damage to internal organs.

Question 43

Smallest circuit breaker or fuse used to protect power circuits in buildings of how much amps and did they offer protection against shocks? ## Footnote Pg 5

Answer 43

Smallest circuit breaker or fuse used to protect power circuits in **15 amps** buildings, but offer **no protection** against shocks.