Question

The photoelectric effect is observed by shining blue monochromatic light having wavelength 450 nm onto a sample of caesium. The collector electrode is biased to a voltage V relative to the caesium potential (a) Use the Internet to look up the workfunction of caesium (b) Find the most negative value of V, the retarding potential, at which a photocurrent may be observed (c) What is the longest wavelength of radiation that would allow photocurrent from the caesium to be observed if V 0? In what part of the electromagnetic spectrum is this radiation? (d) What element has the smallest workfunction? Find several metals that have among the largest workfunctions. Use references or the Internet. (e) Frequently there is more than one workfunction value for a given metal. Look at reference data and explain reasons for this.

Answer 1

The solution is given in the attached image.

The possible explanation is provided.