Q2: Science Long Test 1

Question 1

What is electricity?

Answer 1

the interaction of electric charges

Question 2

Do protons have a positive or negative charge?

Answer 2

Positive

Question 3

Do electrons have a positive or negative charge?

Answer 3

Negative

Question 4

What is the law of electric charges?

Answer 4

The attraction or repulsion between objects.

Question 5

Definition of static electricity

Answer 5

The build up of electric charges on an object

Question 6

What is electric discharge

Answer 6

The release of electrons from a fully charged object to a positive charged object known as the conductor

Question 7

What is an electric current

Answer 7

The flow of electrons - this can be on a conductor

Question 8

Direct Current (DC) Definition

Answer 8

The flow of electricity in one direction only.

Question 9

Alternating Current (AC) Definition

Answer 9

Flows in one direction, then reverses repeatedly.

Question 10

What is a conductor?

Answer 10

A material that allows current to flow through easily

Question 11

What is an insulator?

Answer 11

A material that resists the flow of electric current.

Question 12

He was the one who discovered that electric currents produce a magnetic field

Answer 12

Hans Orested

Question 13

They discovered that if an electric current produces a magnetic field, then a changing magnetic field creates an electric current.

Answer 13

Michael Faraday and Joseph Henry

Question 14

What is an electromagnet?

Answer 14

A coil of wire around an iron rod

Question 15

What is induced EMF

Answer 15

EMF created because of the change in the magnetic environment around the conductor

Question 16

Define EMF

Answer 16

The “force” that pushes electrons through the conductor, creating an electric current || However, there is not really any force, it’s just pressure.

Question 17

This law states that the change in strength of magnetic field (magnetic flux) induces a current, hence creating induced emf

Answer 17

Faraday’s Law

Question 18

This law states that the magnetic field of the induced current will push back/repel against the change of the original magnetic field

Answer 18

Lenz Law

Question 19

What does Coulomb’s Law state?

Answer 19

The size of charges and distance between electric charges are the factors in determining the strength of the electric force.

Question 20

Function of Magnets in an AC Generator

Answer 20

The magnet is used as an magnetic field to create electricity

Question 21

Function of Armature Coil in an AC Generator

Answer 21

Produces an electric current when it turns in a magnetic field

Question 22

Function fo Slip rings in an AC Generator

Answer 22

Used to transfer electric power from stator to circuit

Question 23

Function of Carbon Brushes in an AC Generator

Answer 23

Conducts an electric current, and makes contact with slip rings

Question 24

Function of the load in AC generator

Answer 24

thing being powered by the generator

Question 25

Function of Magnets in DC Generator

Answer 25

The stator which is the stationary component found in electric motors and generators

Question 26

Function of Armature Coil in DC Generators

Answer 26

Connected in series to enhance the sum of current

Question 27

What happens to Mechanical energy in a Motor/Generator

Answer 27

Gets converted into Electrical Energy

Question 28

Function of Commutator/Slip Ring in a DC Generator

Answer 28

Applies an electric current to the windings

Question 29

What are the 3 stages in producing electricity?

Answer 29

Generation, Transmission, and Distribution

Question 30

Describe the step down transformer

Answer 30

More coils on the primary side than the secondary side 3:1 ratio

Question 31

Describe the step up transformer

Answer 31

More on the secondary side, less on the primary side 1:3 ratio

Question 32

Explain how the transformer operation works.

Answer 32

When AC Voltage is applied to the primary coil, the current flows through it creating a change in magnetic field. 2. The magnetic core guides the change of magnetic field 3. the magnetic field circles the secondary coil and induces a magnetic current. → the result of this is that the voltage applied to the primary coil is therefore transformed into a different voltage in the secondary coil.

Question 33

Explain Mutual Inductance

Answer 33

Principle which allows transformers to work.

Question 34

An Electric Motor does what?

Answer 34

Does the reverse of a generator: Changes electrical energy into mechanical energy.