TLO 1

Question 1

Describe the basic composition of an atom and the concept of electron flow

Answer 1

Electricity is electron flow through materials and devices.
Movement of free electrons provides electric current flow in a metal conductor.
Electron energy level is proportional to the distance from the nucleus.

Question 2

Define Electrostatic Force

Answer 2

Unlike charges attract and like charges repel. Holds electrons in orbit.

Question 3

Define Potential Difference

Answer 3

How large the electrostatic force is between two charged objects.

Question 4

Define Electromotive Force (EMF)

Answer 4

Force of the electrostatic field.
-Results in the ability to do work. -Defined as the sum of the potential differences of all charged particles in the electrostatic field.

Question 5

Define Ion Charge

Answer 5

Lose electrons, become positively charged.
Gain electrons, become negatively charged.

Question 6

Define Coulomb’s Law

Answer 6

Strength of the attraction or repulsion force between two charged objects depends upon two factors:
Amount of charge on each object. Distance between the objects.

Question 7

Define Conductor

Answer 7

Materials with electrons loosely bound to their atoms. Good conductors have one valence electron, such as copper, silver and gold.

Question 8

Define Insulator

Answer 8

Materials with electrons tightly bound to atoms that require large amounts of energy to free the electrons. Valence shells filled with eight electrons. Rubber, plastics, glass and dry wood.

Question 9

Define Resistor

Answer 9

Materials that conduct electricity, but offer opposition to current flow. Neither good conductors nor good insulators. Constructed of materials including Carbon, Silicon, Germanium, Tin and Lead.

Question 10

Define Voltage

Answer 10

Voltage indicates potential difference between charged objects.
The difference of potential causing 1 Coulomb of current to do 1 Joule of work.
The amount of force required to force 1 ampere of current through 1 Ω of resistance.

Question 11

Define Current

Answer 11

Movement of electrons.

Question 12

Define Electron Current Flow

Answer 12

Electron flow is the direction of the electron flow from the negative side to the positive side.

Question 13

Define Conventional Current Flow

Answer 13

Conventional current flow is opposite the electron flow. It is the flow of the positive charges (hole left by electrons flow).

Question 14

Define Direct Current (DC)

Answer 14

DC current flows continuously in the same direction.

Question 15

Define Alternating Current (AC)

Answer 15

AC current periodically reverses direction. (Sine wave)

Question 16

Define Real Sources

Answer 16

Current or voltage supply that has some losses associated with it.

Question 17

Define Ideal Sources

Answer 17

Theoretical concept of current or voltage supply that has no losses and is a perfect voltage or current supply.

Question 18

Define Resistance

Answer 18

Opposition to current flow. (Ohm)

Question 19

Define Conductance

Answer 19

The opposite, or reciprocal, of resistance is conductance.
The ability to conduct current. (Siemens)
G = 1/R

Question 20

Define Power

Answer 20

The rate at which work is done or the rate heat is generated. (Watt)
P = I²R

Question 21

Define Inductance

Answer 21

The ability of a coil to store energy, induce a voltage in itself and oppose changes in current flow. (Henry)