Flashcards in Paper 2 corrections Deck (11):
1
How is the mean drift velocity and number density connected
The current is constant, therefore v ∝ n-1. The mean drift velocity is therefore smaller.
2
Experiment for finding the I and r
Diagram 1. Labelled diagram of glass block & ray box 2. Incident and refracted rays shown 3. Normal shown and correct i and r
Procedure 1. Block placed on paper 2. Incident and refracted rays marked 3. Angles measured using a protractor
Analysis 1. sin i and sin r calculated 2. sin i against sin r graph plotted 3. Straight line of best fit drawn 4. gradient = refractive index (n) 5. Error bars drawn to find the gradient
3
Describe how he wavelength of light changes from glass to water
The ray is refracted away from the normal, therefore the refractive index of water is less than the refractive index of glass or speed of light in water is greater than the speed of light in glass.
The frequency remains constant.
v = f λ and therefore the wavelength of light increases as it travels from glass to water.
4
coherence
Waves / sources with constant phase difference.
5
State how you can use an oscilloscope to check the frequency of a wave in a double slit exsperiement
Place a microphone close to loudspeaker and connect it to the oscilloscope.
Measure the number of divisions between neighbouring peaks of the signal. (AW)
The separation between the neighbouring peaks should be 3.6 divisions.
6
What changes when the amplitude of the transmitted waves is halved
Position does not depend on intensity, hence no change.
Intensity decreases by a factor of 4.
7
State the effect intensity has on the current in a photocell
The rate of photons incident on M is doubled.
The rate of emission of photoelectrons / current is doubled.
8
Describe the motion of a particle in terms of the force it experiences when the field is a magnetic field
The force is right angles to the motion / velocity. The particle describes a circle in the plane of the paper.
9
Describe the motion of a particle in terms of the force it experiences when the field is an electric field
Particle experiences a force perpendicular to motion / velocity.
It moves to the right and either comes out or goes into the plane of the paper (in a parabolic path).
10
State what is meant by induced nuclear fussion
The splitting of a (uranium) nucleus as a neutron is absorbed (into two fragment nuclei and neutrons).
11