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Flashcards in Overall quick test Deck (89):
1

Give three reasons why geologists didn't accept Wagner's theory.

Any three from: he wasn't a geologist, supporting evidence was limited, it could be explained more simply, the movement of continents wasn't detectable.

2

What provides the heat in the Earth's core?

The decay of radioactive elements

3

What evidence do scientists study to obtain information about the Earth's age?

Fossils of plants and animals, and radioactivity of rocks

4

What type of wave, generated by an earthquake, travels through the liquid outer core of the Earth?

P-waves

5

In plate movement, old rock is destroyed by which process? (HT)

Subduction

6

What two factors produce rock stripes of alternating polarity? (HT)

Deep-floor spreading and the changing polarity of the Earth's magnetic field every million year.

7

What type of wave is a sound wave?

Longitudinal

8

A water wave has a frequency of 5 hertz and a wavelength of 0.1m. What is the speed of the wave?

0.5m/s

9

What is a student describing if they tell you the number of waves produced each second?

Frequency

10

A station broadcasts signals at a frequency of 30MHz. If the speed of light is 3 x 10 {8} m/s, what is the wavelength? (HT)

10m

11

What is the difference between moons and asteroids?

Moons orbit planes; asteroids orbit the Sun

12

What two methods are used to measure the distance of stars?

Relative brightness and parallax

13

How is the wavelength of light changed if the source of light is moving away?

The wavelength increases (red shift)

14

Why is it hard to predict the fate of the Universe?

The amount of mass in the Universe is hard to measure

15

How do spectra give evidence for red shift? (HT)

They're displaced towards the red end of the spectrum

16

What is the relationship between the distance of galaxies and the speed at which they're moving away? (HT)

They're proportional to one another

17

Which proton transfers the most energy: infrared or ultraviolet?

Ultraviolet

18

Name 3 ionising radiations.

Ultraviolet radiation; gamma; x rays

19

Give 2 ways in which radiation can damage cells.

Any 2 from: the heating effect (sunburn); it can cause ageing of the skin; it can cause mutations; it can cause radiation poisoning

20

What is the ozone layer?

A thin layer of gas in the Earth's upper atmosphere that absorbs some of the sun's harmful ultraviolet radiation

21

How does the radiation emitted by the Earth compare with that emitted by the Sun? (HT)

The radiation from the Earth has a lower principal frequency

22

Give 3 reasons why the intensity of a beam of photons decreases the distance.

Some photons are scattered and reflected by other particles; some photons are absorbed by particles; photons spread out as they travel

23

What change in the Earth's atmosphere causes global warming?

An increase in the percentage of greenhouse gases, such as carbon dioxide, in the atmosphere

24

Why is optic fibre useful when sending infrared and light radiation?

They can travel huge distances without becoming significantly

25

What is noise?

Unwanted frequencies in a signal (random variations)

26

How is an analogue signal different from a digital one?

Analogue signals can have any value; digital signals only have two ('1' or '0')

27

Why doesn't noise affect digital signals? (HT)

Even with noise, it's clear which parts of the signal represent 1 and 0, so it can be regenerated without noise

28

How is data, collected about the Earth's changing temperature, used? (HT)

It is used with climate models to look for patterns in the possible causes of global warming

29

Why is electricity distributed through National Grid at high voltage?

To reduce the energy losses

30

Name five primary energy sources used to generate electricity.

Any five from: coal; gas;oil; nuclear; wind; water (hydroelectric, tidal, wave); solar; biofuel

31

The burning of fossil fuels releases carbon dioxide into the atmosphere. What to problems does this contribute to?

Global warming; climate change

32

How is a voltage induced between the ends of a coil?

By rotating a magnet near the coil

33

What are the three forms of energy that are involved in a hydroelectric power station?

Potential energy; kinetic energy; electrical energy

34

How much energy is transferred by a 60W lamp in 3 seconds?

180J

35

How efficient is an electric motor that uses 400J/s to give 100J/s of useful energy?

25%

36

An electric fire was left on for 30 minutes and the total energy transferred was 1.5kWh. What is the power rating of the fire? (HT)

3kW

37

A student plots a speed-time graph. The graph gives a horizontal straight line. What does that tell you about the acceleration?

It was zero - the speed was constant

38

A man walks North at 2m/s for 10 seconds, then rests for another 20s. What is his displacement? (HT)

20m North

39

With a rocket, the engine pushes gas backwards. What is the name of that force?

Action

40

A force of 12N acts on a truck for two seconds. What is the change in momentium?

24kg m/s

41

Give 3 examples of safety devices used in cars.

Crumple zone; seat belt; air bag

42

A cyclist of mass 60kg is moving at a speed of 4m/s. How much kinetic energy does the cyclist have?

1/2 (half) x 60 x 4{2} = 480J

43

A person weighing 800N gains 16,000J of gravitational potential energy as they're carried up in a lift. How high did they go? (HT)

20m

44

A person has 800J of kinetic energy. If they have a mass of 100kg, how fast are they travelling? (HT)

4m/s

45

If a Perspex rod is rubbed with a cloth, it loses electrons. What charge will the rod now have?

Positive

46

If a battery of 12V is connected across a bulb and a current of 3A flows through it, what is the resistance of the bulb?

4 *omega sign thing*

47

How could the relationship between the current and voltage across a component be described if the resistance is constant?

They're proportional

48

A 12V batery is connected across a resistor of resistance 24(omega sign thing). What current flows? (HT)

0.5A

49

Why does a component heat up when a current flows? (HT)

There are more collisions between the flowing electrons and the vibrating ions, giving a higher resistance. This leads to more heat being produced by the resistor

50

What principle do generators use to generate electricity?

The principle of electromagnetic induction

51

What is the power of a 12V lamp in a circuit where a 0.5A current flows?

6W

52

In a transformer, what induces a voltage across the secondary coil?

A changing magnetic field

53

A transformer has a primary coil of 200 turns. If the transformer changes 12V to 240V, how many turns must be on the secondary coil? (HT)

4000 turns

54

A 60W light bulb has a 240V power supply connected across it. What current flows? (HT)

0.25A

55

What particles are found in the nucleus?

Protons and neutrons

56

Name the three types of ionising radiation.

Alpha;Beta;Gamma

57

What is the type of radiation that passes through paper but is stopped by 3mm of aluminium?

Beta

58

Give 2 sources of background radiation.

Any two from: radon gas; medical; food; cosmic rays; gamma rays; nuclear industry

59

What is meant by the term 'half-life'?

The time it takes for the radioactivity to halve

60

Describe an alpha particle? (HT)

An alpha particle is a helium nucleus and consists of 2 protons and two neutrons

61

A radioactive source has an activity of 288 counts per minute and a half-life of 6 hours. What will the activity be after 24 hours? (HT)

18 counts per minute

62

If a radioactive nucleus emits a beta particle, how does the nucleus change? (HT)

It has one more proton and one less neutron than the original nucleus

63

How is intermediate-level waste stored?

It is mixed with concrete and stored in big containers

64

What particles were used to bombard the gold foil in the Rutherford-Geigar-Marsden experiment?

Alpha particles

65

What conclusion was made about the nucleus from the Rutherford-Geigar-Marsden experiment?

Gold atoms (and therefore all atoms) consisted of mainly empty space with a small, dense core called the nucleus. The charge on the nucleus was positive.

66

What element is used in control rods in a nuclear reactor? (HT)

Boron

67

What elements can be used in a nuclear power station fuel rod? (HT)

Uranium or plutonium

68

What makes the stars appear to move from east to west?

The rotation of the Earth from west to east

69

What two angles describe the positions of a star?

The angles of declination and right ascension

70

What is a lunar eclipse?

When the Earth passes directly between the Sun and the Moon, casting a shadow onto the moon

71

What is a sidereal day? (HT)

The time taken for the Earth to rotate 360 degrees on its axis

72

Why don't eclipses occur every month? (HT)

The Moon doesn't orbit the Earth in the same plane as the Earth orbits the Sun

73

What changes when waves cross the boundary between one medium and another and are refracted?

The speed of the wave and the wavelength

74

What is the power of a lens with a focal length of 0.2m?

power = 1 / 0.2 = 5 dioptres

75

Why is a mirror usually used in an astronomical telescope?

It can be made larger than a lens and therefore gathers more light. This gives greater detail in the image

76

A refracting telescope has a magnification of x3. If the focal length of the objective lens is 0.6m, what is the focal length of the eyepiece? (HT)

0.2m

77

What 2 things does the observed intensity of a star depend on?

Luminosity and the distance from the Earth

78

What does the brightness of a Cepheid variable depend on?

The frequency/period of the pulses

79

What did Shapley believe about the Universe?

That the universe contained only one big galaxy

80

What did Edwin Hubble discover about the Universe by observing Cepheid variable stars in distant galaxies?

That the universe is expanding

81

A nearby galaxy is 0.88Mpc from Earth. If the Hubble constant is 70kn s{-1} Mpc{-1}, what is the speed of recession? (HT)

distance x hubble constant = speed of recession

0.88Mpc x 70km s{-1} Mpc {-1} = speed of recession

61.6km/s = speed of recession

82

How can Cepheid variables be used to estimate the star's luminosity? (HT)

By measuring the frequency of the pulses

83

What two things does the pressure of a gas depend on?

The number of collisions per second betewen the particles and the walls of the container; the momentum of the particles.

84

What is the value of absolute zero?

-273 degrees celsius

85

How is energy transferred from the core of a star to the photosphere?

By convection and photons of radiation

86

What information can be obtained by examining the Sun's spectrum?

The elements present in the SUn

87

What element is mainly present in the core of a star that becomes a supernova?

Iron

88

In the Hertzsprung-Russell diagram, what two types of star don't appear in the main sequence?

White dwarfs and red giants (accept red supergiants

89

The speed of light 3 x 10{8}m/s. How much mass must a star lose to radiate 1.8 x 10{17} joules of energy? (HT)

2kg