K.C.S.E Physics Q & A - MODEL 2004PP2QN07

K.C.S.E Physics Q & A - MODEL 2004PP2QN07

 a) i) What is photoelectric effect?
ii) You are provided with the following:
a photocell, a source uv light, a rheostat, a source of e.m.f, a milliammeter, a voltmeter and connecting wires. Draw a circuit diagram to show how photoelectric effect may be demonstrated in the laboratory.
b) In a photoelectric effect experiment, a certain surface was illuminated with radiation of different frequencies and the stopping potential determined for each frequency
​Table 2 shows the results obtained.

(i) Plot the graph of the graph of stopping potential (y-axis) against frequency.
(ii) Determine Planks Constant, h, and the work function,of the surface given that eVs = hf- hfo where e= 1.6x 10^-19 coulomb and hf = 0(thita)fo is the lowest frequency that can cause photoelectric effect.
c) A surface whose work function = 6.4 x 10^-19 joules is illuminated with light of frequency 3.0 x 10 ¹⁵HZ
Find the maximum Kinetic energy of the emitted photoelectrons (Use the Value of H obtained in b(ii)

answers