AMPLITUDE,FREQUENCY ,PERIODIC TIME,WAVELENGTH
-To define :amplitude,frequency,periodic time and wavelength -To describe data representation in a telephone line
A wave is described using the following terms Amplitude (A); It is the maximum displacement that an electrical signal can attain. In the above example the amplitude is one. Frequency (F); It is the number of cycles made by a signal per second i.e. how many waves per second It may be measured in: Hertz 1 Hz means 1 wave per second Kilohertz 1 kHz is 1,000 waves per second Megahertz 1 MHz is 1 million waves per second. Gigahertz1 GHz is 1,000 million waves per second. Periodic Time; It is the time taken for one complete oscillation. Wavelength; means the length of one wave i.e. the distance from any point on a wave to the same point on the next cycle of the wave. It can be measured in Km, m , cm, e.t.c DATA REPRESENTATION ON A TELEPHONE LINE Digital signals are unable to travel across traditional analogue telephone wires. To transmit digital signals across telephone lines, the signals need to be converted to analogue signals. Signal modulation is the conversion of digital signals to analog signals for transmission over analog media. Signal demodulation is the conversion of analog signals back to digital signals on the receiving end Signal modulation and demodulation is performed using a device known as modem. It is a modulator and demodulator i.e. it convert digital signals to analog signals for transmission over telephone lines. On the receiving end it converts the analog signals back to digital signals.
