## write short note on time domain and frequency domain representation ofa signal.

**Ans. **A signal f(t) can be represented in terms of relative amplitudes of various frequency components present in signal. this is possible by using exponential fourier Series.this is a frequency domain representation of the signal.the time domain representation is specifies a signal at each instant of time. this means that a signal f(t) can be specified in two equivalent ways-

(1) time domain representation; where f(t) is represented as a function of time. graphical time domain representation is termed as waveform.

(2) the frequency domain representation; where the signal is defined in terms of its spectrum.

any of the above 2 representations uniquely specifies the function i.e., if the signal f(t) specified in time domain, we can determine its spectrum.conversely, if the spectrum is specified, we can determine the corresponding time domain of a signal. in order to determine the function, it is necessary that both amplitude spectrum and phase spectrum are specified. however, in many cases, the spectrum is either real or imaginary, as such as only and amplitude plot is enough as all frequency components have identical phase relation.