MES Basic Electricity Chapters 1-3

What is this symbol?

• Transformer

• DC Power Source

• Contactor

• AC Power Source

Answer explanation

This symbol represents a DC power source, or battery.

If a positively charged body is in contact with a negatively charged body, the electrons will flow from the ___.

• positive to the negative body until both become negative

• positive to the negative body until both become positive

• negative to the positive body until one becomes neutral

• negative to the positive body until both have equal charges

Water is made by chemically combining two atoms of oxygen with one atom of hydrogen.

• True

• False

Answer explanation

It's H2O, not O2H!!!

Substances that allow the free motion, or flow, of electrons are called ___.

• conductors

• resistors

• insulators

• transformers

Answer explanation

A conductor, or electrical conductor, is a substance or material that allows electricity to flow through it. In a conductor, electrical charge carriers, usually electrons or ions, move easily from atom to atom when voltage is applied.

A(n) ______ is capable of identifying hazards or working conditions which are unsanitary and has authorization to take corrective measures to eliminate them.

• supervisor

• maintenance personnel

• competent person

• shop foreman

Answer explanation

An OSHA "competent person" is defined as "one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them" [29 CFR 1926.32(f)].

What is this symbol?

• Time delay relay, opens after delay

• Normally closed high temperature switch

• Normally open sail switch

• Normally closed float switch, opens on rise in water level

Answer explanation

High temperature limit switch, commonly found on heating appliances.

The red button in the center of this switch, is the manual reset.

In a cell, the liquid, called the ________, is forcing electrons from one of the plates and depositing them on the other plate.

• electrolyte

• acid

• water

• hydrogen

Answer explanation

The Electrolyte is the medium that provides the ion transport mechanism between the cathode and anode of a cell.

Electrolytes are often thought of as liquids, such as water or other solvents, with dissolved salts, acids, or alkalis that are required for ionic conduction.

A(n) ___ consists of a zinc container with a carbon rod in the center surrounded by an electrolyte, ammonium chloride, in paste form.

• wet cell battery

• deep cycle battery

• dry cell battery

• lithium ion battery

Answer explanation

Look at the picture, just look at it!

What is this electrical symbol?

• Transformer

• Relay

• Coil

• Capacitor

Answer explanation

Transformer

A ___ type battery is a storage battery composed of secondary cells using sulphuric acid for the electrolyte, lead peroxide for the positive plate, and lead for the negative plate.

• lithium ion

• lead acid

• lead sulfate

• dry cell