PHYSICS: ELECTRICITY AND MAGNETISM

Question 1

Electric charge

Answer 1

-two types of electric charge exist in our universe: positive and negative
-some particles have no charge (neutrons)
-some have a positive charge (protons)
-some have a negative charge (electrons)
-like charges repel each other, and unlike charges attract each other

Question 2

Coulomb’s law

Answer 2

-applies to this force of attraction and repulsion (like charges repel each other and unlike charges attract each other)
-coulombs law found that the electrical force between two charges is proportional to the product of the two charges
-therefore, if one charge is doubled, the electric force is doubled
-if both charges are doubled, the electric force increases four times
-coulomb also found that the electric force varied inversely as the square of the distance between the charges -thus, when the distance between two forces doubles, the force between them decreases to 1/4 of the original force
-when the two forces are brought closer together, the force between them increases

Question 3

Magnetism

Answer 3

-electricity is closely related to magnetism, which is a force of attraction
-all magnets have a north and south pole, each of which attracts its opposite and repels its similar pole

Question 4

Magnetic fields

Answer 4

-exist whenever electric charges are moving
-when the moving charges are in a wire that loops, a torque results
-this effect is the basis for electric motors

Question 5

Generator

Answer 5

-a device that converts mechanical energy, such as water coming down a waterfall, into electric energy

Question 6

Electrical potential energy

Answer 6

-can be compared to the gravitational force associated with an objects position
-because of the force, the object has potential energy
-similarly, electrical potential energy is associated with the potential interaction of two objects’ charges

Question 7

Potential difference

Answer 7

-the change in electrical potential energy

Question 8

Transformer

Answer 8

Device that changes the potential difference of electricity

Question 9

Voltage

Answer 9

-another term for potential difference
-a measure of the electrical energy available

Question 10

Voltmeter

Answer 10

A device that measures the potential difference between two points in an electrical circuit

Question 11

Current

Answer 11

Electricity moving through a circuit

Question 12

Ampere

Answer 12

Unit used to measure electrical current

Question 13

Ammeter

Answer 13

Device that measures the current going through any specific point on the circuit

Question 14

Resistor

Answer 14

-wave by which the ability to flow through a circuit is limited
-resistor lowers voltage

Question 15

Two types of circuits

Answer 15

-a series circuit has all its resistors in a row so that all current must travel through all resistors
-in a parallel circuit, all the resistors are arranged side-by-side so that they are all at the same voltage

Question 16

Electromagnet

Answer 16

-the connection between electricity and magnetism can be seen in an electromagnet
-ex. a wire wrapped around a nail and then connected to a battery will carry a current
-this will generate a magnetic field perpendicular to the circuit
-increasing the number of coils increases the strength of the magnetic field