Page 30 - Spotlight A+ Physics Form 4.5

Form
5 Physics Chapter 7 Quantum Physics

(b) Based on the experiment conducted, state
(i) the manipulated variable
(ii) the responding variable
(iii) the constant variable.

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(c) Draw a graph of V against –—.
λ
(d) Based on your graph in (c), state the relationship between V and λ.
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(e) Calculate the gradient, k of the graph V against –— in S.I. unit.
λ
hc
–19
(f) If k = –— where e = charge of an electron (1.60 × 10 C)
e
c = speed of light in vacuum (3.00 × 10 m s )
8
–1
Calculate Planck's constant, h
If you are unable to carry out the experiment described above, you can answer this question by using the data
obtained from the readings of the millivoltmeter shown in Figure 1.2.

1 2 1 2 1 2
0 3 0 3 0 3
V V V

λ = 467 nm λ = 567 nm λ = 586 nm
V = V V = V V = V

1 2 1 2
0 3 0 3
V V

λ = 623 nm λ = 793 nm

V = V V = V
CHAP
7 Figure 1.2

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