MOST IMPORTANT QUESTIONS AND ANSWERS FOR CHSE 12TH PHYSICS CHAPTER COMMUNICATION SYSTEMS

 

WEIGHTAGE 5 MARKS

 

Elements and basics

Elements of a communication system:

 

Introduction to the basic components like the source, transmitter, channel, receiver, and destination. 

Basic terminology:

 

Key terms such as signal, amplitude, wavelength, and frequency are defined. 

Bandwidth:

 

The difference between the highest and lowest frequencies in a signal, and the bandwidth of a transmission medium. 

Modulation

Need for modulation:

 Why modulating a signal is necessary to make it suitable for transmission. 

Types of modulation:

Amplitude Modulation (AM): Variation of the carrier wave's amplitude. 

Production of AM waves: How an AM wave is generated. 

Detection of AM waves: How an AM wave is received and demodulated. 

Other types: Mention of frequency modulation and phase modulation. 

Propagation of waves

Propagation of electromagnetic waves:

 How radio waves travel through the atmosphere. 

Ground wave:

 Propagation along the Earth's surface. 

Sky wave:

 Propagation by reflection from the ionosphere. 

Space wave:

 Propagation in a straight line, used for line-of-sight and satellite communication. 

Antenna size:

 The relationship between the size of an antenna and the effective power radiated.