Page 13 - 1202 Question Bank Physics Form 5

Section B

Answer all questions.

6. (a) Diagram 6.1 shows the transistor symbol.

C

B

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E
Diagram 6.1

(i) State the type of transistor above. [1 mark]
(ii) Write an equation to relate I , I and I . [1 mark]
B C E
(iii) Explain the principle of operation of transistor above using a simple circuit. [4 marks]
(b) Diagram 6.2 shows a transistor circuit for activating the fire alarm.

Diode Switch
Thermistor
Bell
100 kΩ 5V

Extra high
tension
1 kΩ R

Diagram 6.2
Explain the operation of the transistor circuit as an auto switch for a fire alarm system. [4 marks]

(c) Diagram 6.3 shows a circuit with transistor used as a sound amplifier.

R

S
Q
P

Diagram 6.3

97
Question 6:
(c) On all four electronic devices, the loudspeaker is an important electronic device for the sound amplifier. SOS TIP

Chp 5_1202 QB Physics F5.indd 97 07/01/2022 2:09 PM