P2 - Electricity And Magnetism

Question 1

What is a charge?

Answer 1

A property of an object that decides what happens when the object enters electrostatic fields.

Question 2

What happens when like charges meet?

Answer 2

They repel.

Question 3

What happens when unlike charges meet?

Answer 3

They attract.

Question 4

What is an electric field?

Answer 4

An area around a charged object where other charges will feel forces on them.

Question 5

What is a current?

Answer 5

The flow of charges per second through a system.

Question 6

How do objects charge?

Answer 6

Objects charge due to an imbalance in their charged particle numbers which they gain from other objects.

Question 7

How does a switch work?

Answer 7

It creates a gap in the circuit to stop the current flowing through and then closes up to complete the gap when the switch is turned on.

Question 8

What unit is a current measured in?

Answer 8

Amperes/Amps (A)

Question 9

What are the circuit symbols of: a cell a battery a bulb a buzzer a motor and a switch?

Answer 9

Question 10

What is potential difference?

Answer 10

It is the amount of energy transferred per charge as seen by the equation; V (potential difference in voltages) = W (work done in joules) / Q (amount of charge in couloumbs)

Question 11

What unit is a potential difference measured in?

Answer 11

Voltage

Question 12

What component measures potential difference?

Answer 12

Voltmeter

Question 13

What measures current?

Answer 13

Ammeter

Question 14

What is a rating?

Answer 14

The potential difference a component either generates or requires to function.

Question 15

What is a series circuit?

Answer 15

A circuit that is built solely on a single branch.

Question 16

What is a parallel circuit?

Answer 16

A type of circuit with multiple branches and loops.

Question 17

Current: In series circuits.

Answer 17

The current is constant and the same throughout the circuit.

Question 18

Current: Parallel Circuits.

Answer 18

The current in parallel circuits are shared between the branches. Each branch has their own share of the current and they all add up to the total. (Eg: The total current in the circuit is 6A and the circuit has two branches. The ammeter on each branch reads 3A. 3A + 3A = 6A

Question 19

Voltage: Series Circuits

Answer 19

The voltage in series circuits of each component will be shared of the total potential difference. (Eg: The single branch has two bulbs and a cell which produces 6V of “p.d.”. The bulbs have to share them so the first bulb takes 4V for it’s rating which only leaves 2V for the other bulb.)

Question 20

Voltage: Parallel Circuits

Answer 20

Each branch has the same potential difference store as the total and components share the stores in their corresponding branches. (Eg: The battery makes 6V and each branch of the circuit gets 6V as a result. The components in the branches have to share the 6V only among the branch. Bulb1 in branch 1 will take all 6V for their branch. However Bulb2 in branch 2 will not be affected and still have the total reserved for it of 6V.

Question 21

What is the resistance of a component?

Answer 21

The resistance value tells how difficult it is for a current to flow through a component and how much energy it needs to do so.

Question 22

What is the equation of resistance?

Answer 22

Current (A) = Potential Diff. (V) / Resistance (Greek Omega)

Question 23

How does resistance relate to conductiveness?

Answer 23

Conductive materials have loose electrons and will have low resistances.

Question 24

How do the poles of magnets interact?

Answer 24

Like poles repel while unlike poles attract.

Question 25

What does an object need to be in order to be attracted to a magnet?

Answer 25

The object needs to be a magnetic material such as Iron.

Question 26

What is a magnetic field?

Answer 26

Magnetic fields are areas that do work on magnetic objects or other magnetic fields.

Question 27

How could you see a magnetic field?

Answer 27

By using either: - Iron fillings - Or small compasses

Question 28

What does a magnetic field look like?

Answer 28

Arrows that go out from the north pole of a magnet to its south pole.

Question 29

What is an electromagnet?

Answer 29

A wire with current flowing through it which produces a magnetic field.

Question 30

Why do we loop around and make coils of electromagnetic wires?

Answer 30

A single straight wire has an independent and week magnetic field. By coiling them up, the fields get stacked and merge into a bigger one.

Question 31

What is a core?

Answer 31

A core is a rod of magnetic material which is placed through electromagnetic coils to focus and densify the magnetic fields of the coils. It makes them much stronger.

Question 32

How could you create a stronger electromagnet?

Answer 32

By: -Adding more loops to the coil and stacking more electromagnetic fields this way. -Increasing the current flowing through the electromagnetic wire. -Adding a core.