Physics Revision

Question 1

What is a control variable?

Answer 1

A variable that is kept the same to ensure a fair test.

Question 2

What is an independent variable?

Answer 2

The variable you change in an experiment.

Question 3

What is a dependent variable?

Answer 3

The variable you measure in response to the independent variable.

Question 4

What is a categoric variable?

Answer 4

A variable with values that are labels, like colours or types.

Question 5

What is a discrete variable?

Answer 5

A variable with numerical values that can only be specific whole numbers.

Question 6

What is a continuous variable?

Answer 6

A variable that can have any numerical value within a range.

Question 7

How do you plot categoric data?

Answer 7

Using a bar chart.

Question 8

How do you plot continuous data?

Answer 8

Using a line graph or scatter graph.

Question 9

What is energy?

Answer 9

The ability to do work or cause change.

Question 10

Name different stores of energy.

Answer 10

Kinetic, thermal, chemical, gravitational, elastic, nuclear, electrostatic, magnetic.

Question 11

State the conservation of energy principle.

Answer 11

Energy cannot be created or destroyed, only transferred or transformed.

Question 12

What is the formula for efficiency?

Answer 12

Efficiency = (Useful energy output / Total energy input) x 100

Question 13

What is power?

Answer 13

The rate of energy transfer. Power = Energy / Time.

Question 14

What is a kilowatt-hour?

Answer 14

The energy used when 1 kW of power is used for 1 hour.

Question 15

What is a fuel?

Answer 15

A substance that stores energy which can be released to do useful work.

Question 16

How does a power station work?

Answer 16

Fuel is burned to heat water, producing steam that turns a turbine connected to a generator.

Question 17

Give an advantage and disadvantage of wind power.

Answer 17

Advantage: Renewable. Disadvantage: Weather-dependent.

Question 18

Give an advantage and disadvantage of coal.

Answer 18

Advantage: Reliable. Disadvantage: Non-renewable and polluting.

Question 19

Name some common forces.

Answer 19

Gravity, friction, air resistance, upthrust, tension, normal force.

Question 20

What is a free-body diagram?

Answer 20

A diagram showing all the forces acting on an object.

Question 21

What is equilibrium?

Answer 21

When all forces are balanced and there is no change in motion.

Question 22

What is a resultant force?

Answer 22

A single force that represents the effect of all forces acting on an object.

Question 23

What is Newton’s 2nd Law?

Answer 23

Force = Mass x Acceleration.

Question 24

What is the difference between mass and weight?

Answer 24

Mass is the amount of matter; weight is the force due to gravity.

Question 25

What is the formula for weight?

Answer 25

Weight = Mass x Gravitational Field Strength.

Question 26

What is work done?

Answer 26

Work = Force x Distance.

Question 27

What is gravitational potential energy?

Answer 27

GPE = Weight x Height.

Question 28

What is upthrust?

Answer 28

The upward force on an object in a fluid.

Question 29

How do you calculate density?

Answer 29

Density = Mass / Volume.

Question 30

What causes air resistance?

Answer 30

Collisions of air particles with a moving object.

Question 31

When does friction occur?

Answer 31

When two surfaces are in contact and moving or trying to move.

Question 32

State Hooke’s Law.

Answer 32

Force = Spring Constant x Extension.

Question 33

What are simple machines?

Answer 33

Devices like levers, pulleys, gears that make work easier.

Question 34

What is the purpose of a simple machine?

Answer 34

To reduce the effort needed to do work.

Question 35

Name the objects in our solar system.

Answer 35

Planets, moons, asteroids, comets, the sun.

Question 36

What is the order of the planets?

Answer 36

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Question 37

What causes the seasons?

Answer 37

The tilt of the Earth’s axis as it orbits the sun.

Question 38

What causes the phases of the moon?

Answer 38

The changing positions of the moon, Earth, and sun.

Question 39

What causes tides?

Answer 39

The gravitational pull of the moon and sun on Earth's oceans.

Question 40

What are spring and neap tides?

Answer 40

Spring tides are strong tides during full/new moon; neap tides are weak tides during quarter moons.

Question 41

What is charge?

Answer 41

A property of matter that causes it to experience a force in an electric field.

Question 42

What is an electron?

Answer 42

A negatively charged subatomic particle found in atoms.

Question 43

How does an electroscope work?

Answer 43

It detects electric charge using metal leaves that repel when charged.

Question 44

How does a Van de Graaff generator work?

Answer 44

It builds up static electricity by transferring electrons to or from a metal dome.

Question 45

What is an electric field?

Answer 45

A region around a charged object where other charges experience a force.

Question 46

What is a conductor?

Answer 46

A material that allows electric current to flow through it.

Question 47

What is an insulator?

Answer 47

A material that does not allow electric current to pass easily.

Question 48

What is current?

Answer 48

The flow of electric charge measured in amperes (A).

Question 49

What is potential difference?

Answer 49

The energy transferred per unit charge, measured in volts (V).

Question 50

What is resistance?

Answer 50

A measure of how much a component resists the flow of current, measured in ohms (Ω).

Question 51

What is Ohm's Law?

Answer 51

V = I × R (voltage = current × resistance).

Question 52

How does current behave in a series circuit?

Answer 52

It is the same everywhere in the circuit.

Question 53

How does current behave in a parallel circuit?

Answer 53

It splits between branches and adds up to the total current.

Question 54

What materials are magnetic?

Answer 54

Iron, nickel, cobalt, and some of their alloys.

Question 55

What happens when opposite poles of magnets are brought together?

Answer 55

They attract.

Question 56

What happens when like poles of magnets are brought together?

Answer 56

They repel.

Question 57

What does the magnetic field around a bar magnet look like?

Answer 57

It goes from the north pole to the south pole in curved lines.

Question 58

What is Earth's magnetic field used for?

Answer 58

Navigation using compasses.

Question 59

What is a temporary magnet?

Answer 59

A material that becomes magnetic when placed in a magnetic field.

Question 60

What is an electromagnet?

Answer 60

A magnet created by passing current through a coil of wire.

Question 61

How do you increase the strength of an electromagnet?

Answer 61

Add more coils, increase the current, or use an iron core.

Question 62

Give a use of electromagnets.

Answer 62

In electric bells, motors, MRI machines, or scrap yard magnets.

Question 63

What type of wave is light?

Answer 63

A transverse wave.

Question 64

What is a longitudinal wave?

Answer 64

A wave where particles vibrate parallel to the direction of the wave.

Question 65

What is a transparent material?

Answer 65

A material that allows all light to pass through.

Question 66

What is a translucent material?

Answer 66

A material that lets some light through but scatters it.

Question 67

What is an opaque material?

Answer 67

A material that does not let light pass through.

Question 68

What does 'luminous' mean?

Answer 68

An object that gives off its own light.

Question 69

What does 'non-luminous' mean?

Answer 69

An object that does not produce its own light.

Question 70

How does a pinhole camera work?

Answer 70

It uses a small hole to project an inverted image onto a screen.

Question 71

What is the law of reflection?

Answer 71

Angle of incidence = angle of reflection.

Question 72

What happens when light enters a denser medium?

Answer 72

It slows down and bends towards the normal.

Question 73

Why does light refract?

Answer 73

Because it changes speed when moving between materials.

Question 74

What is total internal reflection?

Answer 74

When light reflects entirely inside a medium instead of passing through.

Question 75

What is dispersion?

Answer 75

The splitting of white light into a spectrum of colours.

Question 76

What does a filter do to light?

Answer 76

It only lets certain colours through and absorbs the rest.

Question 77

Why does a red apple appear red?

Answer 77

Because it reflects red light and absorbs other colours.

Question 78

Name parts of the eye and their functions.

Answer 78

Cornea (focuses), lens (fine focus), retina (detects light), optic nerve (sends signals to brain).

Question 79

How do we see colour?

Answer 79

Cones in the retina detect different wavelengths of light.