During an experiment, light of different frequencies is radiated onto a silver cathode of a photocell and the corresponding maximum speed of the ejected photoelectrons are measured - NSC Physical Sciences - Question 10 - 2019 - Paper 1
Question 10
During an experiment, light of different frequencies is radiated onto a silver cathode of a photocell and the corresponding maximum speed of the ejected photoelectro... show full transcript
Worked Solution & Example Answer:During an experiment, light of different frequencies is radiated onto a silver cathode of a photocell and the corresponding maximum speed of the ejected photoelectrons are measured - NSC Physical Sciences - Question 10 - 2019 - Paper 1
Step 1
10.1 Define the term photoelectric effect.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The photoelectric effect refers to the phenomenon where electrons are ejected from a metal surface when light of suitable frequency is incident on that surface.
Step 2
10.2.1 Write down the value of the work function of silver.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The work function of silver, extW0, can be deduced from the graph. From the graph, the y-intercept is 7.48×10−19extJ, hence the work function of silver is 7.48×10−19extJ.
Step 3
10.3 Which physical quantity can be determined from the gradient of the graph?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The gradient of the graph is related to the mass of the photoelectron.
Step 4
10.4 Calculate the value of X as shown on the graph.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
From the graph, the value of X can be calculated using the gradient. The gradient is given by:
ext{Gradient} = rac{11.98 \times 10^{-19} - 7.48 \times 10^{-19}}{X - 0}
After calculating, we find:
X=0.9879×1012extm2exts−2
Step 5
10.5.1 The gradient of the graph
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Remains the same.
Step 6
10.5.2 The number of photoelectrons emitted per unit time
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
