2020 Paper 1 (06/02/2025) Flashcards
Quark configurations of π0?
Up anti up, down anti down
Are Neutral Kaon and Neutral Kaon Anti Particle the same?
Kaon has a structure of down anti strange whereas the antiparticle has a structure of strange anti down. This quark structure and the strangeness for kaon being +1 and -1 for an anti kaon mean the particles are not the same
Hadrons, Leptons in regards to strong force?
Hadrons otherwise baryons and mesons experience strong force as they are composed of quarks, whereas leptons don’t as they are not made of quarks
Frequency of EM must be greater than a certain value?
Frequency is related to energy through E = hf. There is a minimum energy of a photon required to remove photoelectron and due to e=hf minimum frequency links to minimum energy
Photoelectric effect why does current become constant for positive voltage?
Theres a constant current reached when all photoelectrons released each second reach an anode and this is due to the anodes pd which means a positive voltage at maximum current. Number of photoelectrons released per second depends on intensity of EM radiation otherwise number of incidents photons, not potential difference
Photoelectric effect in terms of current decreasing as voltage becomes more negative?
Photoelectrons are released with a range of KE. When V is negative photoelectrons lose KE and gain potential energy crossing anode as work is being done to move electrons in opposite direction so less likely to reach anode. As V is increasingly negative fewer photoelectrons released per second have sufficient initial KE to cross anode meaning current decreases.
Changing photoemissive surface and effect on stopping potential?
Smaller work function means kinetic energy maximum increases leads to a higher stopping potential needed to reduce current to 0. Kinetic energy maximum and stopping potential is linked in the equation KE max = eVs
Method to create coherent waves?
Having 2 loud speakers connected to the same signal generator
Moving the between maximum points?
A path difference is introduced where waves become out of phase which decreases amplitude
Coherent factors?
Something is coherent if there’s constant wavelength, frequency and a constant phase difference
Path difference synonym?
Path difference is the same as one wavelength
Decrease of frequency effect?
Wavelength gradually increases and the path difference gets closer to one wavelength and this is because path difference decreases with an increasing frequency. The amplitude gets louder as waves become more in phase with a smaller frequency
Why does chevron distance not consider car coming to rest?
It would assume car in front would take the same time to travel same distance when braking but only difference is reaction time of car behind. Car in front cannot stop instantaneously. Stopping distance is too large and would be insufficient use of space or be ignored by drivers
Disadvantages and Advantages of superconductors in electrical transmission over long distances?
They reduce heat loss (energy transfer) otherwise power loss in cables and have 0 resistance. But, difficult to maintain low temperatures over long distances and they must be kept below critical temperature
Higher refractive index to a lower refractive index?
The speed of the light ray will increase when it’s going from a higher refractive index to a lower refractive index
Points on far side of same peak or trough?
These will be completely out of phase
Impact of one object on another?
To solve a problem like this use the ratios of the momentum
Thermistor temperature increase significance?
When temperature is increased resistance of thermistor will go down and if in a potential divider its share of the voltage will also go down
