Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

physics > november mocks y11 > Flashcards

november mocks y11 Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

what is the equation for speed?

A

speed = distance/time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the equation linking acceleration, change in velocity, and time?

A

acceleration = change in velocity/time taken
a = (v-u)/t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a vector?

A

measures magnitude and direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

is force a scalar or vector?

A

vector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is friction?

A

a force that opposes movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the relationship between unbalanced force, mass, and acceleration?

A

force = mass x acceleration
f = ma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the relationship between weight, mass, and gravitational field strength?

A

weight = mass x gravitational field strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what can thinking distance be affected by?

A
  • tiredness
  • alcohol
  • speed of the car
  • age
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is stopping distance affected by?

A
  • road conditions
  • brake conditions
  • speed of the car
  • mass of the car
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is insulation and how does it protect the user?

A

insulation is when the wires are covered in a insulating material and protects the user by preventing them touching the current-carrying wire, so it lowers the risk of electrocution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is double insulation and how does it protect the user?

A

they have insulated wires and a non-metallic casing which acts as a second layer of protection. double insulated devices do not need to be earthed as the insulating casing cannot be electrified so there is less/no risk of electrocution for the user

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is earthing and how does it protect the user?

A

if an appliance with a metal casing has the live wire come into contact with the casing, it will be electrified and anyone who touches it could be electrocuted. an earth wire is an additional layer of protection in case this happens, as if the metal case gets electrified, the earth wire will provide a low resistance path to the earth, and it will get a surge of current, which means there will be a surge in current in the live wire too. the high current causes the fuse to melt and break and so the circuit is broken, so there is no more electricity going to the appliance, so there is no risk of electrocution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a fuse and how does it protect the user?

A

it is a safety device that is designed to break the circuit if the current becomes to high. it contains a thin wire which will melt if the current goes above a certain value, which isolates the appliance and prevents damage to the device. if the fuse melts, it has to be replaced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a circuit breaker and how does it protect the device?

A

a circuit breaker is designed to break the circuit if the current is too high. it has an push switch which is spring loaded. if the current is too high, the electromagnet will push the switch down by pulling the bolt of the switch (which holds the push switch in place). this will break the circuit, and so it isolates the appliance and prevents the risk of damage to the appliance. they are more reliable and sensitive than fuses, and do not to be replaced, only reset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why does current in a resistor result in an increase in temperature?

A

the energy transfer is a result of electrons colliding with the lattice of atoms in the metal. the metal that the current is flowing through is made of a lattice of ions which are hit by the current of electrons flowing through. when the electron collides, it gives up some energy to the ions in the metal, which causes them to vibrate more and heat up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the domestic uses of the temperature increase in a resistor when current flows in it?

A

it is used in electric heaters, electric hobs, electric ovens, toasters, kettles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the relationship between power, current, and voltage?

A

power = current x voltage
P=IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the relationship between energy transferred, current, voltage, and time?

A

energy transferred = current x voltage x time
E=IVt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the difference between alternating current and direct current?

A

alternating current: current (or voltage) constantly changes direction continuously
direct current: current (or voltage) travels in one direction only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

where is ac supplied from?

A

mains supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is dc supplied from?

A

a cell or a battery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the advantages of a series circuit?

A
  • fewer wires (so it’s cheaper and easier to assemble)
  • uses less power
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are the advantages of parallel circuits?

A
  • components (for example bulbs) may be switched on or off independently
  • if one component breaks, current can still flow through the other parts of the circuit
  • bulbs maintain a similar brightness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how does voltage affect current in a series circuit?

A

higher voltage means higher current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how does the number of components in a series circuit affect current?

A

generally, it means the current is lower in the circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what happens to current when the resistance is changed?

A

when resistance increases, current decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how do light dependent resistors vary with illumination?

A

as illumination increases, the resistance decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how do thermistors vary with temperature?

A

as temperature increases, resistance decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is the relationship between voltage, current, and resistance?

A

voltage = current x resistance
V=IR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is current?

A

the rate of flow of charge (think Q=It)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is the relationship between charge, current, and time?

A

charge = current x time
Q=It

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is electric current in a solid metal conductor?

A

the flow of negatively charged electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what can be used to indicate the presence of a charge in a circuit?

A

a bulb or LED

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how does current act in parallel?

A

it splits at the junctions then comes back together (so it’s conserved)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

how does voltage act in a parallel circuit?

A

it stays the same across every branch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is voltage?

A

the energy transferred per unit charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is a volt?

A

a joule per coulomb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is the relationship between energy transferred. charge, and voltage?

A

energy transferred = charge x voltage
E=QV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what are four examples of conducting materials?

A

aluminium, copper, gold, silver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what are five examples of insulating materials?

A

glass, air, plastic, rubber, wood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what charge does a polythene rod have after being rubbed by a cloth?

A

negative, as both the cloth and the rod are insulators. friction causes a transfer of electrons, so the rod gains electrons from the cloth and becomes negatively charged while the cloth becomes positively charged

42
Q

what are the electrostatic dangers when fueling an aircraft (or vehicle)?

A
  • there is friction between the fuel and the pipe causes a transfer of electrons
  • this could cause a spark which could cause an explosion
43
Q

how can the danger of electrostatic charges be reduced?

A

an earthing wire which carries the charge back to earth

44
Q

how is electrostatic charge used in a photocopier?

A
  • the image of the document is projected onto the positively charge copying plate
  • the plate loses it’s charge in the light areas, but keeps it’s positive charge in the dark areas (eg where the text is)
  • a negatively charged toner powder (the ink) is applied to the plate and sticks where there is a positive charge
  • the toner is transferred onto a new blank sheet of paper
  • the paper is then heated to make sure the powder sticks
45
Q

how does an inkjet printer work?

A
  • the image of the document is projected onto the positively charge copying plate
  • the plate loses its charge in the light areas, but keeps its positive charge in the dark areas (eg where the text is)
  • a negatively charged coloured ink is applied to the plate and sticks where there is a positive charge
  • the ink is transferred onto a new blank sheet of paper
  • the paper is then heated to make sure it sticks
46
Q

what is a longitudinal wave?

A

a wave that oscillates along the direction of travel

47
Q

what is a transverse wave?

A

a wave that oscillates perpendicular to the direction of travel

48
Q

what is the amplitude of a wave?

A

the maximum displacement of the particles from their equilibrium position

49
Q

do waves transfer energy?

A

yes

50
Q

do waves transfer information?

A

yes

51
Q

do waves transfer matter?

A

no

52
Q

what s the relationship between wave speed, frequency, and wavelength?

A

wave speed = frequency x wavelength
v=fλ

53
Q

what is the relationship between frequency and timeperiod?

A

frequency = 1/time period
f=1/T

54
Q

what is the definition of frequency?

A

the number of waves that pass a specific point in a second

55
Q

what is the definition of a time period?

A

the time it takes for one complete wave to pass a specific point

56
Q

can all waves be reflected?

A

yes

57
Q

can all waves be refracted?

A

yes

58
Q

what is the em spectrum in order of frequency (lowest -> highest)?

A
  • radio
  • micro
  • infrared
  • visible light
  • ultraviolet
  • x-ray
  • gamma
59
Q

what is the order of the colours on the visible light spectrum in order of increasing wavelength?

A
  • violet
  • indigo
  • blue
  • green
  • yellow
  • orange
  • red
60
Q

what are the uses of radiowaves?

A

broadcasting and communications because they can be reflected from the earth’s atmosphere

61
Q

what are the uses of microwaves?

A

cooking and satellite transmissions because micro waves can penetrate the earth’s atmosphere

62
Q

what are the uses of infrared?

A

heaters and night vision equipment because infrared waves are easily absorbed by dark, matt objects and have a heating effect

63
Q

what are the uses of visible light?

A

optic fibre cables and photography because they can undergo total internal reflection and cameras are set up to detect visible light

64
Q

what are the uses of ultraviolet?

A

fluorescent lamps, counterfeit detection, sun tan beds because it fluoresces with ultraviolet light

65
Q

what are the uses of xrays?

A

observing the internal structure of objects and materials (including the body) because x-rays can penetrate soft tissue but not bone/other hard tissues

66
Q

what are the uses of gamma rays?

A

sterilising food and medical equipment because gamma kills bacteria

67
Q

what are the dangers of microwaves?

A

can cause heat damage to internal body organs because of internal heating of body tissue

68
Q

what are the dangers of infrared?

A

skin burns

69
Q

what are the dangers of ultraviolet?

A

damage to surface cells and blindness

70
Q

what are the dangers of gamma rays?

A

cancer, cell mutations

71
Q

what part of the em spectrum is ionising?

A

ultraviolet, x-ray, gamma

72
Q

are light waves transverse or longitudinal?

A

transverse

73
Q

what is the law of reflection?

A

the angle of incidence = the angle of reflection

74
Q

what happens when light moves into a denser medium?

A

the light bends towards the normal because it slows down

75
Q

what is the relationship between the refractive index, angle of incidence, and the angle of refraction?

A

n = sin i/ sin r

76
Q

what is the critical angle?

A

the angle of incidence where the ray is refracted along the boundary
or
the angle of incidence above which the light is totally internally reflected

77
Q

what is the relationship between the critical angle and the refractive index?

A

sin c = 1/n

78
Q

are sound waves longitudinal or transverse?

A

longitudinal

79
Q

what is the frequency range of human hearing?

A

20-20,000Hz

80
Q

how can you use an oscilloscope to investigate the frequency of sound?

A
  • connect the oscilloscope to the microphone and check that waveforms are produced and adjust to make sure the wave fills the screen
  • make a sound and press the hold button so the screen freezes
  • measure the distance between two peaks, and then (using the time base) calculate the length of time between the two peaks (the time period)
  • use f=1/T to work out the frequency
81
Q

what is a magnetically hard material?

A

difficult to magnetise, difficult to demagnetise

82
Q

what is a magnetically soft material?

A

easy to magnetise, easy to demagnetise

83
Q

is iron magnetically soft or hard?

A

soft

84
Q

is steel magnetically soft or hard?

A

hard

85
Q

what does current in a conductor produce?

A

it produces a magnetic field

86
Q

how do you make an electromagnet?

A

wrap a coil of wires (solenoid) around a iron core and connect the wires to a power supply

87
Q

when is there a force on a charged particle moving in a magnetic field?

A

when it is not moving parallel to the field

88
Q

how is the force exerted on a current carrying wire used in motors?

A
  • the current in the wire creates a magnetic field
  • this interacts with the existing field from the permanent magnet and exerts a force on the wire
  • so the wire spins
  • every half turn, the split ring commutator changes the direction of the current so the direction of the force changes direction so the coil can continue to spin
89
Q

what is the thumb in flemming’s left hand rule?

A

force

90
Q

what is the index finger in flemming’s left hand rule?

A

magnetic field

91
Q

what is the middle finger in flemming’s left hand rule?

A

current

92
Q

what effect does increased current have on the force on a current carrying wire?

A

force increases

93
Q

what effect does increased magnitude of magnetic field have on the force exerted on current carrying wires?

A

force increases

94
Q

how an voltage be induced in a conductor or coil?

A

when it moves through a magnetic field/ the magnetic field moves around it

95
Q

what effect does the speed of movement have on induced voltage?

A

faster movement means higher voltage

96
Q

what effect does increased power of magnetic field have on induced voltage?

A

higher voltage

97
Q

how is force exerted on current carrying wires used in a loud speaker?

A
  • alternating current from the source passes into the speaker
  • magnetic field created from wire which interacts with permanent magnet
  • this exerts a force on the loud speaker which constantly changes directions so it vibrates
98
Q

how are transformers used in the national grid?

A

powerstation (25,000V)
|
˅
step up transformer
|
˅
power cables (132,000V)
|
˅
step down transformer
|
˅
homes/factories (230V)

99
Q

what is the relationship between input and output voltages and the turns ratio for a transformer?

A

voltage in secondary coils/voltage in primary coils = number of coils in secondary/number of coils in primary
V2/V1 = N 2/N1

100
Q

what is the relationship between imput power and output power?

A

input power = output power
V1I1 = V2I2

physics (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions