Final answer:
To find the quantities for each cathode in a photoelectric-effect experiment, you need to calculate the threshold frequency, work function, stopping potential, and kinetic energy of emitted photoelectrons. The threshold frequency is found using the equation E = hf, the work function is the minimum energy required to remove an electron, the stopping potential is the voltage at which the photoelectron current stops, and the kinetic energy is given by Kmax = hf - ϕ.
Step-by-step explanation:
For each cathode, we can find the following quantities:
a) Threshold frequency: The threshold frequency is the minimum frequency at which electrons can be ejected from the metal surface. To find the threshold frequency, we can use the equation E = hf, where E is the work function and h is Planck's constant. So, the threshold frequency is given by f = E/h. For each cathode, you can substitute the work function value and Planck's constant to calculate the threshold frequency.
b) Work function: The work function is the minimum energy required to remove an electron from the metal surface. It is represented by the symbol ϕ (phi). It can be determined experimentally or given in the question.
c) Stopping potential: The stopping potential is the potential difference at which the kinetic energy of the photoelectrons is completely used up, and they stop moving. It can be measured experimentally by gradually increasing the potential difference until the photoelectron current stops. The stopping potential voltage is equal to the maximum kinetic energy of the photoelectrons.
d) Kinetic energy of emitted photoelectrons: The maximum kinetic energy of the emitted photoelectrons can be calculated using the equation Kmax = hf - ϕ, where Kmax is the maximum kinetic energy, h is Planck's constant, f is the frequency of incident radiation (which can be converted from given wavelength), and ϕ is the work function.
Note: It is important to have the specific values of work functions and stopping potentials for potassium and gold cathodes to perform the calculations.