Post Past Paper 1 Flashcards
What is the only interaction which can change the quark structure?
Weak interaction
Why should all electrons have the same energy during beta decay?
Due to the conservation of momentum
What happens to the waves that meet in phase and antiphase when producing a stationary wave?
Waves in phase constructively interfere - creating antinodes (Points of max amplitude)
Waves in antiphase destructviely interfere - creating nodes (Points of min displacement)
How can we determine whether a given frequency will produce a stationary wave in a pipe with one closed end?
Standing waves are setup when λ = λ/4, 3λ/4, 5λ/4
Hence the frequencies are odd multiples of the lowest frequency: f, 3f, 5f
If the given frequency is not an odd multiple, it wil not produce a standing wave in a pipe with one closed end.
How can we determine whether a given frequency will produce a stationary wave in a pipe with two closed end?
Standing waves are setup when λ = λ/2, λ, 3λ/2
Hence the frequencies are odd multiples of the lowest frequency: f, 2f, 3f
How does air resistance affect the path of a ball kicked into the air?
Air resistance acts in the opposite direction to velocity therefore the ball does work against the air resistance and thermal energy is dissipated.
This means GPE gained will be less and the max height of the ball will be less.
How is a short circuit and an open circuit achieved?
Short: Very low resistance wire between the terminals.
Open: Set the resistance very high.
How is the current found on an IV graph for a given resistance?
Draw a line with the gradient as the reciprocal of the given resistance, take the point where both lines connect.
What interaction do Leptons not experience?
The strong interaction
What relationship should be true for two rays to give a maximum intensity?
The path difference should be a whole number of wavelengths
What is the area under a stress strain graph?
The energy stored per unit volume when a thin wire is stretched.
What is material dispersion?
Waves of different wavelengths travel at slightly different speeds through an optical fibre therefore they will reach the end at slightly different times, this causes pulse broadening.
Monochromatic light stops this.
What is modal dispersion?
Waves enter an optical fibre at slightly different angles therefore the distance each beam has to travel is slightly different. This also leads to pulse broadening as beams reach the end at slightly different times.
Why does the refractive index of the cladding need to have a lower refractive index than the core?
A lower refractive index is needed for TIR to occur and TIR is needed in order to keep the light ray inside and maintain the signal.
How can you determine the refractive index of a material using a semi-circular prism?
Using a protractor and a ray box on white paper, reposition the incident ray until the angle of refraction is 90 degrees.
Then, measure the angle of incidence and sub it into (1/sinθ) to find the refractive index.
Why may the voltmeter read zero if the resistances across a potential divider are the same?
If the resistances are the same, the ratios between the EMF will also be the same. This means that the potential difference will be zero.
What is a fundamental particle?
A particle which is NOT made of smaller component particles (quarks)