2nd half of physics paper 1 gcse

Question 2

What is efficiency?

Answer 2

A measure of how good a device is at changing energy from one form to another.

Efficiency is calculated using the formula: efficiency (%) = (useful energy out / total energy in) x 100.

Question 3

Why will efficiency never be 100%?

Answer 3

Energy is always wasted in the form of heat and friction.

Question 4

What is wasted energy in devices?

Answer 4

Heat to the atmosphere and friction between moving components.

Question 5

How can we reduce wasted energy?

Answer 5

Increase thermal insulation and use oil to reduce friction.

Question 6

What is the formula for Kinetic Energy?

Answer 6

KE = ½ x mass x velocity².

Question 7

What is the formula for Gravitational Potential Energy (GPE)?

Answer 7

GPE = mass x gravitational field strength x height.

Question 8

Under what conditions is the GPE formula valid?

Answer 8

When air resistance and friction are ignored.

Question 9

What happens to GPE lost during a transfer?

Answer 9

It transfers to Kinetic Energy gained.

Question 10

What is conduction?

Answer 10

How good a material is at passing heat through it.

Question 11

What types of materials have good thermal conductivity?

Answer 11

Metals and other conductive materials.

Question 12

What is the effect of doubling the thickness of a material on conductivity?

Answer 12

It generally decreases the rate of heat transfer.

Question 13

What are the stages of a power station for non-renewable energy?

Answer 13

B________, T________, G________, C________, T________, N________, G_____, H _____.

Question 14

List the renewable energy resources.

Answer 14

• Solar
• Wind
• Hydroelectric
• Tidal
• Wave
• Geothermal
• Biomass

Question 15

What are the advantages of solar energy?

Answer 15

Renewable, abundant, low operating costs.

Question 16

What are the disadvantages of wind energy?

Answer 16

Intermittent, noise pollution, impact on wildlife.

Question 17

What is the equation for wave velocity?

Answer 17

Wave velocity = frequency x wavelength.

Question 18

What is the equation for wave velocity in terms of distance and time?

Answer 18

Wave velocity = distance / time.

Question 19

What do longitudinal waves oscillate relative to the direction of energy travel?

Answer 19

Perpendicular.

Question 20

What do transverse waves oscillate relative to the direction of energy travel?

Answer 20

Parallel.

Question 21

What happens to waves at a boundary?

Answer 21

• Reflect
• Transmit
• Absorb

Question 22

What is the auditory nerve’s function?

Answer 22

It takes signals to the brain.

Question 23

How does the ear collect sound waves?

Answer 23

Sound waves are collected by the outer ear (pinna).

Question 24

What is the function of the cochlea?

Answer 24

Turns vibrations into electrical signals.

Question 25

What is ultrasound?

Answer 25

Sound waves with frequencies above human hearing range.

Question 26

What is infrasound?

Answer 26

Sound waves with frequencies below human hearing range.

Question 27

What are seismic waves?

Answer 27

Waves caused by vibrations due to earthquakes.

Question 28

What type of waves are P waves?

Answer 28

Longitudinal waves.

Question 29

What type of waves are S waves?

Answer 29

Transverse waves.

Question 30

What is the critical angle in total internal reflection?

Answer 30

The angle of incidence beyond which all waves reflect back.

Question 31

What is ionizing radiation?

Answer 31

Radiation that causes atoms to become ions, potentially causing damage.

Question 32

What is the half-life of a radioactive substance?

Answer 32

Average time taken for half of the unstable nuclei to decay.

Question 33

What happens during alpha decay?

Answer 33

An alpha particle is emitted, reducing atomic mass by 4 and atomic number by 2.

Question 34

What is beta minus decay?

Answer 34

Occurs when isotopes have too many neutrons; a neutron converts to a proton and emits an electron.

Question 35

What is beta plus decay?

Answer 35

Occurs when isotopes have too many protons; a proton converts to a neutron and emits a positron.

Question 36

What do you measure to find the focus of a lens?

Answer 36

The distance between the center of the lens and the focal point.

Question 37

What is a real image?

Answer 37

Where all rays of light converge on a screen.

Question 38

What is a virtual image?

Answer 38

Where rays of light appear to meet but cannot be projected onto a screen.

Question 39

What is half-life?

Answer 39

The average time taken for half of the unstable nuclei to decay.

Question 40

If the half-life of a radioactive substance is 15 minutes, how long will it take for the activity to fall from 160 Bq to 20 Bq?

Answer 40

45 minutes.

Question 41

How can you decrease your exposure to radioactive substances?

Answer 41

Methods include increasing distance, reducing time of exposure, and using shielding.

Question 42

What is the difference between irradiated and contaminated?

Answer 42

Irradiated = exposure to radiation; Contaminated = radioactive materials present.

Question 43

Which contamination poses a greater risk, those with long or short half-lives? Why?

Answer 43

Long half-lives pose a greater risk due to prolonged exposure.

Question 44

Fill in the blank: Smoke alarms use ______ particles given off.

Answer 44

alpha

Question 45

Fill in the blank: Charged particles move forming a __________.

Answer 45

current

Question 46

What is external radiotherapy?

Answer 46

Uses beams of gamma/x-rays/protons focused on the tumor.

Question 47

Why are several low strength beams directed from a variety of angles in external radiotherapy?

Answer 47

To minimize damage to surrounding healthy tissue.

Question 48

What is internal radiotherapy?

Answer 48

Uses a beta emitter placed inside the body close to the tumor.

Question 49

Why does the patient need to stay alone in the room during internal radiotherapy?

Answer 49

To minimize exposure to others from radiation.

Question 50

What is the role of control rods in a nuclear power station?

Answer 50

To slow the chain reaction.

Question 51

What is nuclear fusion?

Answer 51

When 2 small nuclei join to become a bigger and heavier nucleus.

Question 52

List factors that affect the gravitational field.

Answer 52

* Mass of the objects * Distance between the objects

Question 53

What is weight?

Answer 53

The force of gravity acting on a mass.

Question 54

What is red shift?

Answer 54

The pattern of light lines moving to the red end of the spectrum.

Question 55

What does CMBR stand for?

Answer 55

Cosmic Microwave Background Radiation.

Question 56

Describe CMBR.

Answer 56

Said to be an echo or remnants of heat, it is everywhere and uniform throughout the universe.

Question 57

What theory does red shift support?

Answer 57

The Big Bang theory.

Question 58

What is the Big Bang theory?

Answer 58

All matter was concentrated into a tiny point that expanded rapidly.

Question 59

What is the Steady State Theory?

Answer 59

As the universe expands, new matter is created, keeping the overall appearance constant.

Question 60

What is the life cycle of an average star?

Answer 60

A sequence of stages including main sequence, red giant, and white dwarf.

Question 61

What is a natural satellite?

Answer 61

A celestial body that orbits a planet.

Question 62

Name the planets in order from the sun in our solar system.

Answer 62

* Mercury * Venus * Earth * Mars * Jupiter * Saturn * Uranus * Neptune

Question 63

What are asteroids primarily composed of?

Answer 63

Metal and rocks.

Question 64

What are comets primarily composed of?

Answer 64

Ice, dust, and rock.

Question 65

What is the relationship between orbital radius and period of the orbit?

Answer 65

Longer orbital radius results in a longer period.

Question 66

What is the importance of using sources with short half-lives in hospitals?

Answer 66

To minimize exposure to patients.