2: Getting Down To Basics

Question 1

True or False: There are over 100 kinds of atoms.

Answer 1

True

Question 2

What primarily differentiates atoms, or elements, from each other?

Answer 2

The number of protons and neutrons in their nucleus.

Question 3

Atoms of elements can join together in groups to form what?

Answer 3

A molecule.

Example: Two atoms of hydrogen and one atom of oxygen form a molecule of water.

Question 4

What are found outside the nucleus and carry a negative charge?

Answer 4

Electrons.

Question 5

True or False: The nucleus is positively charged.

Answer 5

True.

Question 6

Will a neutral atom that gains electrons result in a negative or positive charge?

Answer 6

Negative.

Atoms that gain electrons from a neutral state become negatively charged.

Question 7

What is electrostatic attraction?

Answer 7

The phenomenon where negative electrons are held in place by the positive protons in the nucleus.

Question 8

True or false: Particles with like charges attract each other.

Answer 8

False.

Particles with opposite charges attract each other. Like charges repel each other.

Question 9

What is the name for a charged (negatively or positively) atom or molecule?

Answer 9

An ion.

Question 10

What is the process of an atom or molecule becoming (negatively or positively) charged called?

Answer 10

Ionization.

Question 11

What are valence electrons?

Answer 11

The electrons in the outdoor shell of an atom.

These atoms can be put under stress and caused to move to another atom.

Question 12

What is electrical current?

Answer 12

The flow of electrons.

Question 13

What is a conductor?

Answer 13

The substance through which current, or the flow of electrons, moves.

Question 14

What is a coulomb? How is it abbreviated?

Answer 14

The basic unit of charge. 6.28 x 10E18 electrons.

Question 15

What is an ampere? How is it abbreviated?

Answer 15

The rate of flow of electrons. One ampere (A) is one colomb per second.

Question 16

What is the symbol for current?

Answer 16

I (capital i)

Question 17

What is one thousandth of an ampere called? What symbol?

Answer 17

A milliampere.

mA.

Question 18

What is one millionth of an ampere called? What symbol?

Answer 18

A microampere.

uA.

Question 19

What are volts? How are they abbreviated?

Answer 19

A unit of measurement for the work needed to put a charge onto a body by adding electrons to it.

Abbreviated as V.

Question 20

What is potential energy?

Answer 20

The electrons on a charged body.

Question 21

What is voltage? How is it abbreviated?

Answer 21

The difference in potential between two points.

E.

Question 22

What is an mV?

Answer 22

A millivolt. A thousandth of a volt.

Question 23

What is a uV?

Answer 23

A microvolt. A millionth of a volt.

Question 24

What is an insulator?

Answer 24

A poor or non-conductor. A material where the valence electrons are difficult to dislodge.

Question 25

What are the three best conductors?

Answer 25

Silver, copper, and aluminum.

Question 26

What purpose does gold serve in electronic circuits?

Answer 26

Corrosion resistance.

Question 27

What is plasma? Is it a good conductor?

Answer 27

A gas composed of ionized molecules. Yes, very good.

Question 28

How is the tolerance of a component expressed?

Answer 28

The percentage of a marked value.

Question 29

What is tolerance?

Answer 29

The maximum permissible variation from a stated value.

Question 30

What is the unit of resistance? What symbol for a unit of resistance?

Answer 30

Ohms. Symbolized by the Greek letter Omega.

Question 31

What is the symbol for resistance?

Answer 31

R.

Question 32

What is an Ohm?

Answer 32

The resistance of a conductor that will allow one ampere of current to flow when one volt is applied to that conductor.

Question 33

What causes the heating of a wire while current passes through it?

Answer 33

The resistance of the wire to electrons being forced to flow through it.

Question 34

What are watts the measure of? And what is the abbreviation?

Answer 34

Watts are the measure of the amount of heat a resistor can tolerate before it burns up. A watt is abbreviated as W.

Question 35

What factors effect a wife's ability to conduct an electrical current?

Answer 35

Specific resistance, length, diameter, and temperature.

Question 36

What is the difference between fixed, tapped, and variable resistors?

Answer 36

Fixed has a constant value, tapped has several connections with different values, and variable has a movable tap to allow for a range of values.

Question 37

What are two types of fixed or variable resistors?

Answer 37

Composition and wire-wound resistors.

Question 38

What is the acronym for resistor colour code bands?

Answer 38

Better Be Ready Or Your Great Big Venture Goes West Black Brown Red Orange Yellow Green Blue Violet Grey White

Question 39

What do the bands on a resistor stand for?

Answer 39

1 - First digit of resistance value 2 - Second digit of resistance value 3 - Multiplier (silver for 0.01, gold for 0.1) 4 - Tolerance

Question 40

What is conductance? What is the name for a unit of conductance?

Answer 40

The reciprocal of resistance. Siemens, abbreviated as S.

Question 41

How is conductance expressed in an equation?

Answer 41

G.

Question 42

What is an insulator?

Answer 42

A substance with such low conductance that effectively no current can flow through it.

Question 43

True or False: Magnets have much in common with electrical conductors.

Answer 43

True

Question 44

In relation to magnetic fields, in the 1800's it was discovered that electrical current can be made to flow in a conductor by doing what?

Answer 44

1. Moving the conductor through a magnetic field; 2. Moving a magnetic field around a conductor; and 3. Moving both the conductor and the magnetic field.

Question 45

The electrical current in a moving conductor is at a maximum when the conductor is ____________ to the lines of force of the magnetic field?

Answer 45

Perpendicular.

Question 46

Lines of force in a magnetic field run from which point to which?

Answer 46

The north and south pole outside the magnet, then returning south to north inside.

Question 47

What are two types of magnets?

Answer 47

Permanent, made of iron or alloys of steel, and temporary, which are maintained by external forces.

Question 48

What is an electromagnet?

Answer 48

A coil of wire wrapped around a solf iron core. When a current is applied to the wire coil, a magnetic field is generated in the core.