1. Asri did a photoelectric effect experiment using aluminium as the anode. The work function of aluminium is 4.08 eV. X-rays have wavelengths between 10 - 0.01 nm.
(a) What is meant by the phrase ‘work function of aluminium’?
(b) With the aid of a graph (if necessary), explain Asri’s experimental observations and conclusion when he uses
(i) a red incident light of wavelength 650 nm.
(ii) incident X-rays with same intensity but different wavelengths.
(iii) repeat his experiment with incident X-rays with same wavelength but different intensities.
(c) Sketch a graph showing the variation o

Question

1. Asri did a photoelectric effect experiment using aluminium as the anode. The work function of aluminium is 4.08 eV. X-rays have wavelengths between 10 - 0.01 nm.
(a) What is meant by the phrase ‘work function of aluminium’?
(b) With the aid of a graph (if necessary), explain Asri’s experimental observations and conclusion when he uses
(i) a red incident light of wavelength 650 nm.
(ii) incident X-rays with same intensity but different wavelengths.
(iii) repeat his experiment with incident X-rays with same wavelength but different intensities.
(c) Sketch a graph showing the variation o

anonymous · Answer

Ok.. I can help you.. but first tell me what are your thoughts on the questions. lets start with queation a) !

anonymous · Answer

work function is the energy that require to move 1 electron from inside to outside the surface. but i really not sure what that mean.can u enlightened me

anonymous · Answer

thats correct .. 

In order to remove the electron from the surface of the metal, some minimum of energy is required to do that job right?? that min. energy is called as a the work function!.. so unless you give that min. energy.. there shall be no photoelectric effect.. If energy is supplied more than that.. then it absorbs it, uses work function amount of energy to escape from the surface and takes the rest of it as kinetic energy.!

anonymous · Answer

so for the incident red light it will reflect right...then how i want to explain that in my assign.or do i need to do some calculation...

anonymous · Answer

that photoelectric effect means that the reflection of the incident light right.

anonymous · Answer

part (b)
1)Energy of radiation is given by E = hc/w where h is planck's constant ,c is speed of light
  and w is the wavelength of light.
   The energy associated with the red light(just insert the values in above) = 1.9eV  
   This is less than work function and hence no current will flow.

2)The energy range of the x rays are between 124eV (corresponding to 10nm) to       
   124200eV ( corresponding to 0.01nm) . Thus current will flow for the entire range of rays
   But remember value of current depends on intensity only and since intensity is same for
   all wavelengths ,current will be independent of the wavelength.

3) In this case current will change and increase with intensity.

anonymous · Answer

thanks bro...i appreciate your help...thanks