Two different metals, X and Y

PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation

Problem

Two different metals, X and Y, are studied in separate photoelectric experiments. From the straight-line graphs of stopping potential versus frequency obtained in the two experiments, the following numerical values are extracted: Metal X: slope = 4.13×10−15 V⋅s4.13\times10^{-15}\,\text{V}\cdot\text{s}, intercept on the frequency axis = 5.2×1014 Hz5.2\times10^{14}\,\text{Hz} Metal Y: slope = 3.90×10−15 V⋅s3.90\times10^{-15}\,\text{V}\cdot\text{s}, intercept on the frequency axis = 4.6×1014 Hz4.6\times10^{14}\,\text{Hz} (a) Part 1: (i) Calculate the value of Planck’s constant obtained from each slope and find the percentage deviation of each result from the accepted value 6.63×10−34 J⋅s6.63\times10^{-34}\,\text{J}\cdot\text{s}. (b) Part 2: (ii) Determine the work function of each metal in eV. (c) Part 3: (iii) Which of the two data sets gives the more accurate experimental value of hh? State any two plausible experimental reasons for the difference in accuracy.

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