Paper 2 Predicted Topics

Question 1

A driver is using their mobile phone while driving.

Explain how this could affect the stopping distance of the car.

Answer 1

Increases their reaction time.

Longer thinking distance, as driver drives further in the same time without stopping.

Therefore, the stopping distance increases.

Question 2

The road is wet and slippery.

Explain how this affects the stopping distance and why.

Answer 2

A wet and slippery road provides less friction between the tyres and the road surface.

This means the car will take longer to slow down when braking, increasing the braking distance.

As a result, the total stopping distance increases.

Question 3

What is the principle of Conservation of Momentum?

Answer 3

Total momentum before = after in a closed system.

Question 4

What are some safety features that reduce force in collisions?

Answer 4

Crumple zones, seatbelts, airbags.

Question 5

What is a moment in physics?

Answer 5

The turning effect of a force.

Question 6

What condition must be met if an object is balanced?

Answer 6

Clockwise moment = anticlockwise moment.

Question 7

How do levers and gears function?

Answer 7

They multiply force by increasing distance from pivot.

Question 8

What type of waves are EM waves?

Answer 8

Transverse waves.

Question 9

What is the speed of EM waves in a vacuum?

Answer 9

3.0 × 10⁸ m/s.

Question 10

Can EM waves travel through a vacuum?

Answer 10

Yes, unlike sound.

Question 11

List the order of the EM Spectrum from lowest frequency to highest.

Answer 11

• Radio waves (lowest)
• Microwaves
• Infrared
• Visible light
• Ultraviolet (UV)
• X-rays
• Gamma rays (highest)

Question 12

What happens to frequency, wavelength, and energy as you go up the EM spectrum?

Answer 12

• Frequency increases
• Wavelength decreases
• Energy increases

Question 13

What are the uses of Radio Waves?

Answer 13

Broadcasting, TV, radio, communications.

Question 14

Why are Radio Waves effective for long-distance travel?

Answer 14

Long wavelength – travel far, diffract around hills/buildings.

Question 15

What are the uses of Microwaves?

Answer 15

Satellite communication, microwave ovens.

Question 16

Why do Microwaves penetrate the atmosphere?

Answer 16

They are absorbed by water molecules.

Question 17

What are the uses of Infrared waves?

Answer 17

Remote controls, night vision, heaters.

Question 18

Why are Infrared waves used in thermal applications?

Answer 18

Detects/produces heat (thermal radiation).

Question 19

What are the uses of Visible Light?

Answer 19

Vision, photography, optical fibres.

Question 20

Why is Visible Light significant?

Answer 20

Only part of the spectrum visible to the human eye.

Question 21

What are the uses of Ultraviolet (UV) waves?

Answer 21

Tanning lamps, detecting fake banknotes, fluorescent lamps.

Question 22

What is the reason UV waves are used in fluorescent lamps?

Answer 22

UV excites fluorescent materials to emit visible light.

Question 23

What are the uses of X-rays?

Answer 23

Medical imaging (bones), airport security.

Question 24

Why are X-rays effective for medical imaging?

Answer 24

Penetrates soft tissue but absorbed by bones.

Question 25

What are the uses of Gamma Rays?

Answer 25

Cancer treatment, sterilising medical equipment.

Question 26

Why are Gamma Rays used in medical treatment?

Answer 26

Very high energy, kills cells/microorganisms.

Question 27

True or False: Radio waves are generally safe.

Answer 27

True.

Question 28

What potential harm can Microwaves cause?

Answer 28

Can cause internal heating of tissues.

Question 29

What are the dangers associated with Infrared waves?

Answer 29

Can cause skin burns.

Question 30

What are the dangers of Ultraviolet (UV) waves?

Answer 30

Damages DNA, causes skin cancer, eye damage.

Question 31

What risks do X-rays and Gamma rays pose?

Answer 31

Ionising radiation, can cause cell mutation and cancer.

Question 32

What is ionising radiation?

Answer 32

Can remove electrons from atoms, damaging cells.

Question 33

What is the wavelength range of visible light?

Answer 33

* Red: long wavelength (~700 nm) * Violet: short wavelength (~400 nm)

Question 34

What is a convex lens?

Answer 34

Converges light ## Footnote Used in magnifying glasses, cameras, and eyes

Question 35

What is a concave lens?

Answer 35

Diverges light

Question 36

What is the principal focus (F)?

Answer 36

Where rays converge (real or virtual)

Question 37

What is focal length?

Answer 37

Distance from lens to F

Question 38

What does a parallel ray do when it passes through a convex lens?

Answer 38

Goes through F

Question 39

What happens to a ray that passes through the center of a convex lens?

Answer 39

Continues in a straight line

Question 40

What does a ray passing through F on the other side of a convex lens do?

Answer 40

Becomes parallel

Question 41

What is a real image?

Answer 41

Formed on opposite side, can be projected

Question 42

What is a virtual image?

Answer 42

Same side, can’t be projected (e.g., magnified image)

Question 43

What defines ultrasound?

Answer 43

Sound waves with frequency above 20,000 Hz

Question 44

What are some uses of ultrasound?

Answer 44

* Medical imaging (safe for soft tissues) * Industrial flaw detection (e.g. in pipes or welds) * Sonar (e.g. depth of seabed)

Question 45

What is the motor effect?

Answer 45

Current-carrying wire in a magnetic field experiences a force

Question 46

What factors affect the motor effect?

Answer 46

* Magnetic field strength * Current size * Length of conductor

Question 47

What is Fleming’s Left-Hand Rule?

Answer 47

* Thumb: Force * First finger: Magnetic field * Second finger: Current

Question 48

How does a force on each side of a coil affect electric motors?

Answer 48

Causes rotation

Question 49

What does a split-ring commutator do in an electric motor?

Answer 49

Keeps coil rotating in one direction

Question 50

What is the generator effect?

Answer 50

Moving a wire through a magnetic field induces a potential difference

Question 51

What increases the induced current in a generator?

Answer 51

* Stronger magnetic field * Faster movement * More turns in coil

Question 52

What is an alternator?

Answer 52

Uses a rotating coil + slip rings → AC current

Question 53

What is a dynamo?

Answer 53

Uses split-ring commutator → DC current

Question 54

What is a nebula?

Answer 54

Cloud of gas & dust

Question 55

What occurs during the protostar phase?

Answer 55

Gravity pulls material together

Question 56

What happens in the main sequence star phase?

Answer 56

Nuclear fusion starts

Question 57

What are the two types of stars that can form after the main sequence?

Answer 57

* Red giant (low mass) * Red supergiant (high mass)

Question 58

What is the life cycle of a red giant?

Answer 58

Red giant → white dwarf → black dwarf

Question 59

What happens after a red supergiant?

Answer 59

Supernova → Neutron star (if mass moderate) / Black hole (if mass very large)

Question 60

What is red shift?

Answer 60

Light from distant galaxies is shifted to the red end of the spectrum

Question 61

What does red shift indicate about galaxies?

Answer 61

Galaxies are moving away = universe is expanding

Question 62

What evidence does red shift provide for the Big Bang?

Answer 62

* Suggests space is stretching * More distant galaxies = greater red shift → faster speed

Question 63

What is the process by which hydrogen nuclei fuse to form helium in main sequence stars?

Answer 63

Nuclear fusion ## Footnote This process releases massive amounts of energy, which is why stars shine.

Question 64

What elements are formed through fusion in red giants and red supergiants?

Answer 64

Helium → carbon → oxygen → neon, etc. ## Footnote Fusion continues to form heavier elements in these stages.

Question 65

What happens to fusion in low-mass stars like our Sun?

Answer 65

Fusion stops at carbon before becoming a white dwarf.

Question 66

What occurs during a supernova in massive stars?

Answer 66

Massive stars explode, allowing formation of elements heavier than iron. ## Footnote The enormous temperature and pressure during the explosion facilitate this process.

Question 67

What happens to the heavy elements formed in supernovae?

Answer 67

They are ejected into space. ## Footnote These elements eventually become part of new stars, planets, and life.

Question 68

Which elements were made in stars?

Answer 68

All elements heavier than hydrogen and helium (like oxygen, calcium, iron, gold).

Question 69

Fill in the blank: In main sequence stars, hydrogen nuclei fuse to form _______.

Answer 69

helium

Question 70

Fill in the blank: In low-mass stars, fusion stops at _______.

Answer 70

carbon

Question 71

Fill in the blank: In red supergiants, fusion continues up to _______.

Answer 71

iron

Question 72

What is the significance of the elements formed in supernovae?

Answer 72

They enrich gas clouds that form new stars, planets, and life.

Question 73

True or False: All elements heavier than iron are formed during the main sequence phase of a star.

Answer 73

False ## Footnote Elements heavier than iron are formed during supernova explosions.

Question 74

List the stages of element formation in stars.

Answer 74

* Main Sequence Star: Hydrogen to helium * Red Giant: Helium to carbon and oxygen * Red Supergiant: Fusion up to iron * Supernova: Elements heavier than iron

Question 75

What is a transverse wave?

Answer 75

A wave where the oscillations are perpendicular to the direction of energy transfer ## Footnote This definition is relevant for understanding wave behavior in physics.