One mark questions
- What is the meant by the term attenuation ?
- Why ground wave transmission is restricted to 1500 kHz?
- Define critical frequency in sky wave propagation.
- What type of modulation is required in TV transmission?
- Why AM radio reception is affected by electrical disturbances while FM radio reception is not?
- What should be the length of a dipole antenna for a carrier wave of frequency 3 x 108 Hz
- Draw a block diagram showing the basic communication system.
- What is the range of frequencies used for FM radio transmission?
Two marks Questions
- Distinguish analog and digital transmission
- Write the functions of transducer and repeater in Communication systems.
- Distinguish amplitude modulation and frequency modulation.
- Draw a block diagram showing a simple amplitude modulator
- Explain how a message signal is extracted from Amplitude Modulated signal.
- Distinguish Sky wave propagation and Space wave propagation.
- Name the different layers of earth’s atmosphere.
- Mention two ways in which the range of transmission can be increased.
- Explain the term modulation index and describe its significance.
- List four devices used for communication each of which differ from other in the mode of communication.
Three marks questions
- Explain the need for modulation
- Derive an expression for the range of transmission from an antenna of height h.
- Describe the demodulation of AM wave using waveforms and circuit diagrams.