Question 5
- (i) Describe the term transducer.
(ii) List two examples of a transducer.
- Fig. 4 is a device in a television receiver.
- Identify the device in Fig. 4.
- Name the parts labelled V, X and Y.
- State one function each of the parts labelled W and Z.
- State the effect on the output of a television receiver if the device in Fig. 4 is faulty.
Observation
The expected responses were:
(a) (i) A transducer is an electronic device that converts energy from one form to the other.
They are also referred to as sensors.
(ii) Examples of transducers
- Microphones
- Loudspeakers
- Thermocouples
- Video cameras
- Video display unit/cathode ray tube
- Photo diode
- Light emitting diode
- Crystal
- Thermistor
- Strain gauge
- Antenna
(b) (i) Cathode ray tube/picture tube
(ii) V: heater/filament
X: accelerating anode
Y: deflection coil/yoke
(iii) W: provides electron beam for the operation of the device
Z: enables the glowing of the screen
(c) No/poor picture display/output, but sound.
Question 5 required candidates to show with a television transducer, picture/cathode ray tube. While majority of the candidates that attempted the question responded well to the task in the “a’ part, only a few of them gave the expected response to ‘b’ and ‘c’ part.