in signals for eg. say 'cosφ+jsinφ' what does the imaginary part convey. do they practically occur in real time, if so why it is called imaginary.
thanx
j is used by electrical engineers because i was already taken for current. i is the term chosen by mathematicians for the square root of minus one. Back then this was a new idea and the results were called imaginary by them.
In AC signals, the j means a 90 degree phase shift.
All sinusoids are characterised by its peak voltage, and its phase wrt to a reference phase (often set to zero). Expressing AC sinusoids in phasor or complex forms encapsulates these 2 characteristics into a single value.
Alternatively, you can always do things the hard way and express all sinusoids in the usual Acos(wt+Φ).
Hi,
To put it more clear, any signal has two thing associated with it 1) it frequency or Time value i.e the characteristic of the signal how it varies it general pattern etc.. 2) the initial value or phase which describes the exact signal. Two represent both in a single category or representation they used 'j' it is like (x,y) co-ordinate in two dimension.
j means 90 degree phase shift.with out j part u can not create real signal.cosine is made up of two exponential signal having opposite angular velocity.
hi frd
All sinusoids are characterised by its peak voltage, and its phase wrt to a reference phase (often set to zero). Expressing AC sinusoids in phasor or complex forms encapsulates these 2 characteristics into a single value.
Alternatively, you can always do things the hard way and express all sinusoids in the usual Acos(wt+Φ).
j denotes 90 degree phase shift dear
have fun