Weak

Question 1

Conditions for total internal reflection

Answer 1

Light ray is travelling from a MORE optically dense medium to a LESS optically dense medium
Angle of incidence is greater than the critical angle

Question 2

What happens to the current in a circuit if the total resistance of the circuit increases

Answer 2

Current will DECREASE

Question 3

What quantity does not change when a light ray enters a glass block?

Answer 3

Frequency does not change. Wavelength changes and wavespeed changes but frequency does not change

Question 4

Simply, what is Kirchoff’s first law

Answer 4

Total current entering junction= total current leaving junction

Question 5

Simply, what is Kirchoff’s second law?

Answer 5

Sum of emf’s= sum of p.d’s

Question 6

What is plane polarised light?

Answer 6

Oscillations are restricted to one plane of motion
Perpendicular to the direction of travel

Question 7

How can you tell is light is unpolarised

Answer 7

Rotate a polarising filter in front of the light source
Intensity should not change

Question 8

Reasons why a solar panel may not be 100% efficient

Answer 8

-Some energy converted to thermal energy
-Light may not be incident on the panel at 90 degrees
-Intensity of light may be lower due to clouds

Question 9

Why can you not create a good interference pattern with two regular lamps

Answer 9

The light from the lamps is not monochromatic and not coherent
As it does not have a constant phase difference

Question 10

Why are photoelectrons only released above a certain frequency?

Answer 10

1 photon interacts with 1 electron
Electrons absorb the energy from the photons
There is a minimum energy required for photoelectrons to be released
E=hf so there is a minimum frequency for photoelectrons to be released

Question 11

What does intensity of light affect in photoelectric effect

Answer 11

Intensity only affects the number of photoelectrons released
Intensity does not affect the energy of the photoelectrons

Question 12

How can you increase the accuracy of readings

Answer 12

Take repeats and taking a mean

Question 13

One way of improving how you read oscillations of a pendulum

Answer 13

Using a fiducial marker

Question 14

Why would a count rate not reach zero?

Answer 14

Because of background radiation which a data logger will pick up

Question 15

What conditions are needed to measure g by dropping a ball bearing

Answer 15

Air resistance and upthrust should both be negligible

Question 16

Equillibrium definition

Answer 16

Resultant force on an object is zero
Sum of moments about any point is zero

Question 17

Find distance travelled on a velocity time graph

Answer 17

Area under graph

Question 18

Feature of a free body diagram for an object in equilibrium

Answer 18

Resultant force is 0

Question 19

Magnetic flux symbol and unit

Answer 19

Symbol is B and unit is T

Question 20

Magnetic flux density symbol and unit

Answer 20

Symbol is phi and unit is Wb

Question 21

What is weight actually

Answer 21

The reaction acting on us from the floor

Question 22

Features of a radial field

Answer 22

Magnetic field lines get further apart

Question 23

Direction of magnetic field lines

Answer 23

Higher to lower
100V to 0V
100V to -100V

Question 24

Reasons why solar panels may not be suitable for large applications

Answer 24

-Not enough surface area
-Some measurements may be estimated to be too small
-More power may be needed at certain points

Question 25

Pre-Rutherford model of the atom

Answer 25

Positive atom containing equally distributed charge

Question 26

Equation and phrase you never remember

Answer 26

Work done, object 1 will do work on object 2 Work done= force x distance

Question 27

What can you do to approximate trapeziums

Answer 27

Pretending they are rectangles

Question 28

What are the three sides of the triangle for the circular motion vector diagram

Answer 28

v, -v and change in v. Arrows must be top to tail

Question 29

MeV to J

Answer 29

x1000000 and x1.6x10-19

Question 30

What energy is converted by a particle of mass 150MeV/c2

Answer 30

150 MeV

Question 31

Why might a high resolution value from a micrometer be rounded

Answer 31

There can be variations in the positioning of the micrometer

Question 32

Circuit symbol for a heater

Answer 32

Resistor with lines splitting it into 4

Question 33

When comparing results what do you do

Answer 33

State the actual result and not the difference. Or state both probably. Also explain every step

Question 34

What should you say when dealing with a measurement from both sides

Answer 34

Uncertainty is x but since there are 2 measurements absolute uncertainty is 2x

Question 35

When will something travelling in a circle slip

Answer 35

When friction is greater than the required centripetal force

Question 36

What would an external source of something be if it had an effect on readings

Answer 36

Close to the readings acquired in the actual experiment

Question 37

Where is radius or orbit measured from

Answer 37

Centre of orbit, centre of earth, the moon, saturn whatever

Question 38

What happens if a satellite has more energy than required

Answer 38

-Satellite has more kinetic energy at original orbit height -Centripetal force too small to keep on this orbit -Satellite travelling too fast so moves to a higher orbit -r is greater so v must be smaller because if you smash the equations together then yeah

Question 39

Why is a fiducial marker placed at the point of equillibrium

Answer 39

Trolley is moving fastest at this point so uncertainty in starting and stopping stopwatch is the least

Question 40

How to determine max speed of a SHM system

Answer 40

Find T Use T to find w find maximum displacement use v=Aw

Question 41

if v is doubled what happens to Ek

Answer 41

it quadruples

Question 42

Why would making a surface smoother make an object travel further

Answer 42

Frictional forces are reduced

Question 43

How can you justify elastic collisions in a real life situation

Answer 43

Frictional forces are minimal

Question 44

What happens in an elastic collision between A, an object which is moving and a stationary object B

Answer 44

Ek of A is transferred to Ek of B Momentum of A before= momentum of B after

Question 45

What is the most IMPORTANT thing in a table or values

Answer 45

SIGNIFICANT FIGURES EVEN FOR 0 NO 0 0.00

Question 46

Density is

Answer 46

Mass per unit volume

Question 47

How can you criticise results

Answer 47

-No evidence of repeats -Not enough readings -Range is too small -Significant figures are inconsistent

Question 48

Sources of error involving thermometers

Answer 48

-Thermometer may not be same temp as other thing because water temp may not be uniform -Parallax error so temp read incorrectly

Question 49

Improving thermometer results

Answer 49

-Stir liquid -Use a digital thermometer -Put thermometer close to other thing -Thermal equillibrium

Question 50

x intercept of a volume/ temperature graph

Answer 50

-Temperature at which the volume of a gas is 0 -This occurs at absolute zero -Which is the lowest attainable temperature

Question 51

Can uncertainties be reduced with high resolution equipment

Answer 51

Yes but instruments may not be high resolution there could be a systematic error

Question 52

Does drop height affect impact velocity

Answer 52

Yes as a greater drop height leaves more acceleration time for objects to reach terminal velocity

Question 53

If someone makes a conclusion from results, what might it be a good idea to do

Answer 53

Read the results and talk about them in your answer

Question 54

If there are not many results what can you say

Answer 54

More data would be needed for firmer conclusions

Question 55

What happens to observed particles when travelling close to the speed of light.

Answer 55

Their average lifetime increases and their mass increases

Question 56

Do reaction forces act perpendicular to the surface

Answer 56

Not all the time. They can be at an angle if the second object is also at an angle I think

Question 57

If positive and negative products are released in a decay, why must the thing decaying be neutral

Answer 57

Due to the conservation of charge

Question 58

Why is there a mass deficit during decays

Answer 58

E=mc^2 So some mass will have been converted to kinetic energy during the decay

Question 59

If power against time is a sin graph, what is the overall power dissipated

Answer 59

0W

Question 60

Electrostatic force and distance relationship

Answer 60

Inverse square law

Question 61

Outcomes of alpha scattering experiment

Answer 61

Most went straight through, undeflected Some were deflected by small angles Few came straight back

Question 62

If there is height then there is also

Answer 62

Potential energy

Question 63

Types of field

Answer 63

Linear and radial

Question 64

Why would a racecar slip on a bend

Answer 64

There is a resultant force required to maintain circular motion The friction provides a centripetal force When speed increases, friction increases until friction is too large and car will slip

Question 65

What happens to current in a parallel circuit

Answer 65

It splits at junctions, more resistance gets less current

Question 66

Sketch a graph, what might you need to include

Answer 66

Scale, axis

Question 67

Why is parallax not used for large distances

Answer 67

Because the parallax angle would be too small and the percentage uncertainty would be too large

Question 68

How can VERY VERY VERY large distances be determined

Answer 68

change in wavelength of source and in lab found redshift used to find velocity relative to earth hubble's law used to find the distance

Question 69

Something to mention with a binding energy per nucleon graph

Answer 69

If binding energy per nucleon increases, energy is released

Question 70

First thing to mention in a polarisation question

Answer 70

Light from the source is unpolarised (unless it is not)

Question 71

What does a filter rotated

Question 72

How does a polarising filter reduce the intensity of light

Answer 72

By absorbing the perpendicular components of the light

Question 73

What happens as a polarising filter in rotated in front of another polarising filter

Answer 73

Only components of light in the same plane as filter 2 is let through so intensity decreases

Question 74

Photon energy in the photoelectric effect

Answer 74

It must be greater than the work function of the metal

Question 75

Why might not all decays be detected by a Geiger Muller counter

Answer 75

-Radiation is emitted in all directions -Some emitted particles pass through the detector

Question 76

Why might radioactive samples with a long half life be used

Answer 76

Because their activity does not decrease dramatically over time

Question 77

What happens is waves have a path difference of half a wavelength

Answer 77

They are in antiphase