Electricity and Magnetism

Question 1

What is a Magnet?

Answer 1

A metal or rock, usually with high iron content. It creates an invisible field of force around themselves. This field attracts other magnets and certain metals

Question 2

What are the end of magnets called and what colours are they?

Answer 2

A magnet has 2 Poles (ends) Red = north. Blue = South.

Question 3

When do magnets attract and when do they repel?

Answer 3

If the poles are identical (south and south or north and north) they repel, if they are opposite (north and south) they attract.

Question 4

What is Lodestone?

Answer 4

Lodestone is a rock that is rich in iron and is naturally magnetic.

Question 5

What metals can become magnetic?

Answer 5

Iron, cobalt, and nickel are all metals that can become magnetic.

Question 6

True or False: The earth is not a giant magnet.

Answer 6

False. The earth is a giant magnet.

Question 7

What are magnetic domains?

Answer 7

Magnetic domains are tiny magnetic crystals inside a magnet.

Question 8

What happens if you break a magnet?

Answer 8

If you break a magnet, the domains are still all lined up meaning each half will still have a north pole and a south pole and become its own magnet.

Question 9

What is magnetization?

Answer 9

If you run a nonmagnetic iron nail through a magnetic field, you can turn it into a magnet, this is magnetization.

Question 10

True or False: Magnetic fields of attraction look different to magnetic fields of repulsion.

Answer 10

True.

Question 11

What is a Solenoid?

Answer 11

You can take advantage of electromagnetism by creating a Solenoid. A solenoid consists of a wire coiled around a piece of metal, usually iron. When a current is passed through a wire, a magnetic field is created. The metal in the core of the solenoid strengthens the magnetic field.

Question 12

What is Current and how is it measured?

Answer 12

Current is a measure of the number of charges per second travelling around and electric circuit. It is measured in Ampere (Amps) (A).

Question 13

How many Milliamps is 1 Amp?

Answer 13

1Amp = 1000Milliamps (mA)

Question 14

What is Voltage and how is it measured?

Answer 14

A measure of the amount of energy in an electric circuit. Voltages is measured in Volts (V)

Question 15

What is the difference between series and parallel circuits?

Answer 15

A series circuit has one conductive pathway whereas a parallel has multiple conductive pathways. Also, with a parallel circuit, voltage stays the same and current is split. Whereas with a series circuit the voltage splits and the current stays the same.

Question 16

What are the formulas for solving resistance, current (I) and voltage?

Answer 16

V = I X R
I = V/R
R = V/I

Question 17

What is Ohms law?

Answer 17

The law states that there is a direct proportionality between the voltage applied across some conductors and the resultant electric current. (As the voltage goes up, the current increases, as the resistance goes up, the current decreases)

Question 18

What is Electrical current?

Answer 18

Electrical current is the movement of electrons around a closed circuit. This flow is continuous not singular as in static electricity. The “conventional” current flow is from the positive to the negative, which is associated with the idea of positive charges moving. However, electrons are the only charges that actually move in a circuit. The flow of electrons in the circuit is from the negative to the positive.

Question 19

True or False: The pathway travelled by electrical
current is called a circuit.

Answer 19

True.

Question 20

What must a circuit have?

Answer 20

An energy source, pathway and a load.

Question 21

How does a current move?

Answer 21

Currents are always described as moving around a circuit from the positive (+) terminal of the energy source to the negative (-) terminal of the energy source.

Question 22

True or False: A circuit does not have to be closed to work.

Answer 22

False. A circuit must be closed to work.

Question 23

What is DC?

Answer 23

Direct Current: electrons flow in one direction only. Battery powered circuits are DC circuits.

Question 24

What is AC?

Answer 24

Alternating Current: Current changes direction 50 times every second. Mains power in our homes are AC.

Question 25

What is amps measured with and what are volts measured with?

Answer 25

Amps: Ammeter or AmpMeter
Volts: Voltmeter

Question 26

Can a parallel circuit still work if one part fails?

Answer 26

Yes. But a series cannot.

Question 27

What is a Resistor?

Answer 27

Resistors are devices placed deliberately in circuits to create a precise quantity of resistance. They control the current by reducing the size of the current. Their colour rings indicate the value of resistance in Ohms.

Question 28

Who is Georg Ohm?

Answer 28

Georg Ohm was a German physicist who discovered the relationship between voltage, current and resistance.

Question 29

What causes Static Electricity?

Answer 29

Friction causes a separation of charges which leads to static electricity. As Static Electricity is a charge moving once from one object to another and staying there.

Question 30

What is Electrostatic charge?

Answer 30

Objects usually have an equal number of charges (balanced). however, you can separate these charges, this is called electrostatic charge.

Question 31

True or False: Just like magnets, electrostatic charges can attract or repel each other.

Answer 31

True: like charges repel, opposite charges attract.

Question 32

What is Static Electricity?

Answer 32

It just means that bodies become charged because of gain or loss of electrons and that this difference remains “static.” When the charges move back, creating a discharge, it is often seen or felt as a spark with both light and sound being generated. This movement of charges is uncontrolled and chaotic.

Question 33

True or False: Lightning is not a form of static electricity.

Answer 33

False: Charges are separated in the atmosphere by friction due to high winds. When they have built up enough collective charge, they are attracted to the ground (which is neutral) and the charges move to the ground, in a chaotic motion. This disruption of potential energy due to the large number of charges and the large distance to the ground creates a torrent of charges so powerful that they emit light and dislocate the air in a loud sound – this is lightning.

Question 34

What type of Electricity is the movement of electrons around a closed circuit. (Hint: This flow is continuous not singular as in static electricity.)

Answer 34

Electrical Current.

Question 35

What is an Electrical Conductor?

Answer 35

A material through which charged particles are able to move. (Allow the flow) Example: copper or steel.

Question 36

What is an Electrical Insulator.

Answer 36

A material that does not allow the movement of charged particles. (Resist the flow) Example: plastic or rubber.