This section provides a quick preview of questions from the document. It may not display every question or the complete wording of each one. For the full content, including diagrams, tables and other information, view the original PDF above.
Q1— Section header —
1.1Determine the frequency to which the receiver is tuned if the frequency at the input of the intermediate frequency (IF\ stage measures 455 kHz. (4\
1.2Determine the RMS and average values of the oscillator output. (6\ [10]10
Q2— Section header —
Q3— Section header —
3.1Draw the circuit diagram of an inverting operational amplifier applied as an inverting audio amplifier stage with gain control, coupling capacitors and thermal compensation. (10\
3.2Draw the circuit diagram of an inverting operational amplifier that has a constant gain. (2\
Q3— Section header —
Q4— Section header —
4.15\ in the ANSWER BOOK.
4.1An operational amplif ier used as integrator uses a/an (inductor/capacitor/ resistor\ in the feedback path.
4.2(Space/Ground/Short\ waves are used at frequencies above 30 MHz.
4.3The modulation (factor/index/reflex\ is associated with FM.
4.4With regard to the frequency response curve of an IF amplifier, the narrower the bandwidth, the (less/more\ selective the circuit.
4.5emphasis network is normally inserted between the detector and the (IF/audio\ amplifier.
4.6The adjustment of the tuned circuits in the IF stage is done to obtain maximum (voltage/gain/current\ for a given bandwidth.
4.7The Yagi antenna has an (omni directional /uni directional \ radiation pattern.
4.8A/An (even/slow/fast\ recording speed results in a good frequency response magnetic tape.
4.9Automatic gain control (AGC\ is obtained from the output of the (IF/detector/ audio\ stage in the receiver.
4.10(Alpha/Be ta/Delta\ is an example of time division multiplexing used for digital data communication.
4.11The (oscilloscope/frequency counter/sweep generator\ measures distortion.
4.12Refraction is the (reflecting/bending/absorption\ of an electromagnetic wave as it passes from one medium to another.
4.13The angle between the E fields and H fields in an electromagnetic wave is /90 /180
4.14The (capstan/pinch roller\ drives the tape in a tape recorder.
4.1515
Q5— Section header —
5.1Pulse amplitude modulation (PAM\ (2\
5.2Pulse width modulation (P (3\
5.3Pulse position modulation (PPM\ (3\ [8]8
Q6— Section header —
6.1Briefly explain why AG C is needed and how it is achieved (4\
6.2The purpose of RF amplifier is to amplify a signal with a small amplitude to a usable level. xplain the terms selectivity and
Q7— Section header —
7.1Draw a neat, labelled circuit diagram of a ratio detector. (8\
7.2State the main purpose of a detector in a receiver. (2\
7.3What is the frequency of the IF signal in an AM receiver? (1\
7.4Which section of the AM receiver produces the most gain and selectivity? (2\
7.5Why does FM have a better signal noise ratio than AM? (2\ [15]15
Q8— Section header —
8.1Tropospheric ducting (5\
8.2Tropospheric scatter (5\ [10]10
Q9— Section header —
9.1Explain how capstan drive works with regard to tape recorders. (6\
9.2Give the advantages of feeding the audio signal together with an alternating current bias signal to the recording head. (4\ [10] TOTAL:10