It was worded like ' If all the light of the laser was absorbed/used (something like that) then what would the photocurrent be'.
We were given the Power output of the laser and the wavelength of the light.
I tried finding the number of electrons emitted per second (
) and then using
to find the current.
Firstly I tried finding the Kinetic energy of the light (we also had the work function of the metal) and then finding a voltage from it by
, but what I was doing didn't really seem to make much sense.
Also is there an allowed value of hc (planck's constant x speed of light) we can use for workings and to put in our calculators because it takes a lot of time typing everything in your calculator constantly.
For the constants I would try to store h and c individually in your scientific calculator (h in both units, along with charge and mass of electron, and G)
Type the number, find the 'sto' (store) feature on your calc, and then press the button with whatever capital letter you want to store it under (or google storing constants for your specific calculator model to find instructions)
for ideas, I think i had:
A: gravitational constant
B: charge on electron
C: speed of light
D: mass of electron
X: planck's constant (eVs)
Y: planck's constant (Js)
M: nothing
after you do that, you can just press alpha>letter and put these letters in your formulas rather than typing out the big numbers
ANYWAY in terms of the actual question, i wouldn't expect it on a real exam but you were on the right track
number of photons that hit the metal = number of photoelectrons emitted (assuming everything is absorbed, and that individual photons are above the threshhold frequency)
number of photons:

and

times n for total power, so


is equal to number of photoelectrons:
e/t)
fortunately t's cancel

if i havent made mistakes that should work, use whatever value of h and e is consistent with the units P is given in to make sure it works out