Page 12 - 1202 Question Bank Physics Form 5

PAPER 2

Section A

Answer all questions.

1. Diagram 1 shows the thermal emission and production of cathode ray generation.
SPM
CLONE X Y

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e
e

Discharge tube

– +
E.H.T.
Diagram 1

(a) What is meant by the term thermionic emission? [1 mark]

(b) State the name of X and Y. [2 marks]

(c) Why vacuum is created in discharge tube? [1 mark]

(d) State two factors which affects the rate of thermionic emission. [2 marks]

(e) Potential difference, V = 2 500 V is supplied between X and Y, HOTS Applying
(i) calculate the velocity of electron. [2 marks]

(ii) state any change in speed of electron if the potential difference between X and Y increased?
[1 mark]

92 Question 1:
SOS TIP (b) Using the concept of conservation of energy, the work done (W = eV) is equal to the increase in kinetic energy mv . )
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1
2
2

Chp 5_1202 QB Physics F5.indd 92 07/01/2022 2:09 PM