Question

Data for the stopping potential 56 for the photoelectric effect of an unknown metal are given in the table. Using graph paper (or Excel), plot0 the kinetic energy eV₀ of the electrons vs. the incoming photon energy (hc/l). From the linear fit of this graph, find the slope value, work function j and threshold photon energy.

V0	l (nm)	hc/l (eV)
0.49	1250	0.99
0.74	1000	1.24
1.15	750	1.65
1.98	500	2.48
4.46	250	4.96

Answer 1

From the linear fit, Slope value = 2e-19

Work function = The intersection of the curve on the y-axis = 8e-20 eV

Threshold photon energy = The intersection of the curve on the x-axis (set y=0 in the equation to find the value) = 0.4 eV