Unit 1 atomic structure

an electrical circuit has a voltage of 50 v and a resistance of 5 ohms. What is the value of current?

10 A

an electric circuit has a resistance of 20 ohms. the current is measured to be 6 a. How many volts are applied to the circuit?

120

A toaster is listed as 1560 W. When it is plugged into a 120 V circuit and starts to make toast, how many amperes will it draw?

13

approximately how many horsepower is an electrical device listed as 3,000 watts

4

An electric motor is running on 120 v. The current is measured to be 2 A. How many ohms of resistance is the motor

60

What type of current reverses it's direction of flow at regular intervals?

Alternating

What type of current is flows in only one direction?

Direct

Matter can only exist in only two states: solid or liquid

False

unit of resistance to current flow is the ____

Ohm

Matter has mass and occupies space

always true

one coulomb per second is equal to one

ampere

What is the smallest part of an element that still retains the properties of that element?

an atom

Alternating current is described as ____.

bidirectional

The theory stating that current flow is produced when an electron from one atom knocks electrons of another atom out of orbit is generally called the _____ theory

bump

a complete circuit is often referred to as a _____ circuit

closed

what law states that the force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them?

coulombs law

What is the maximum number of valance electrons in an atom

eight

What part of an atom has a negative charge?

electron

the theory concerning current flow that is most widely accepted as being correct is the ____ flow theory

electron

What are the three principle parts of an atom

electron, proton, neutron

Electrical current is the flow of _____

electrons

what did william gilbert call material that could be charged

elektriks

Voltage flows through an electric circuit like water flows through a pipe.

false

during normal operation of a typical 120-volts appliance circuit, current flows through the hot, grounding, and neutral conductors

false

the greater the difference in the number of electrons between the negative and positive terminals, the greater the what?

force of repulsion and attraction

a semi-conductor contains ____ valance electrons

four

what standard prefix in engineering notation indicates multiplication by 1,000,000,000

giga

any object repelled by a piece of what rubbed on silk would have a positive charge

glass

The neutral conductor is also referred to as the _____ conductor.

grounded

what contains seven or eight valance electrons

insulator

in bump theory what happens to the striking electrons energy

it gives its energy to the electron being struck

if an atom containing two valance electrons is struck by a moving electron, what happens to the energy of the striking electron

it is divided between the two valance electrons

the velocity of AC through a conductor is _____ the speed of light

less than

what is the most common method of producing electricity

magnetism

The smallest part of a compound that still has the properties of that compound is a

molecule

conventional current flow theory states that current flows from the most positive point to the most

negative point

the nucleus of an atom contains

neutrons and protons

The statement "in a DC circuit, the current is directly proportional to voltage and inversely proportional to resistance" is known as ________ law

ohms

a conductor is made from a material that contains between ______ valance electrons

one and three

the valance shell of an atom is the _____ shell

outer

producing electricity from light involves the use of particles called

photons

What part of an atom has a positive charge?

proton

the atomic number of an element is the number of _____ in the nucleus

proton

the basic law of physics states that like charges ______ and opposite charges ____.

repel;attract

What force is demonstrated in objects with like charges?

repulsion

What causes a wire to become warm when current flows through it?

resistance

an insulator is a material containing _____ valance electrons

seven or eight

What type of circuit generally occurs when the conductors leading from and back to the power source become connected

short

which of the following is one of the two most common materials used in the production of electronic components

silicon

The grounding prong of a plug should never be cut off or bypassed.

true

a grounding conductor helps prevent a shock hazard in the event that an ungrounded, or hot, conductor comes in contact with the case or frame of an appliance

true

the amount of potential necessary to cause one coulomb to produce one joule of work is a

volt

what is another term for electromotive force (EMF)

voltage

the amount of electrical power being used in a circuit is measured in ____

watts

If a circuit is open, current _____ flow.

will not