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Monday, February 7, 2011

Signals and Systems-Time Scaling and Time Shifting

I have find this part as the most confusing one among the students.
Though everyone feels that it is easy (which indeed is true), yet mistakes are often commited
Take a look at the following note:

 Time Shifting and time scaling of x(t) to y(t) = x(at+b)
 It is better to first time shift and then time scale because time shift is w.r.t to “t” and not “at”
Take the following example:-
Suppose we are provided with x(t) and we have to find y(t) = x(2t+3)










A step by step procedure is shown below:-







Take another example of a GATE EE 2010 question:

 Q.  Given f(t) and g(t) as shown below:







The simplest approach is:-
Take g(t) = f((at + b),
From graph, g(3) = 1 = f(a.3 + b) and g(5) = 1 = f(a.5 = b)
We can see from graphs that left step of f(t) give left step of g(t) and right step of f(t) gives right step ofg(t).
Hence we have:
a.3 + b = 0  and a.5 + b = 1 which yield ,
a =1/2 and b=-3/2
Therefore g(t) = f(t/2 – 3/2). Ans (d).

Sunday, January 30, 2011

Industrial Drives and Control - Experiments

Welcome back to classes after the sports week.
Though most of us had spent the last week away from sports. Inspite of that, I think most of us had enjoyed break to fullest in their own way 

I have uploaded a file for my classmates at NIT Patna 
Please find below the link for experiment sheets of IDC Lab
http://ifile.it/gbl24yz

The uploaded file is just the scan copy of lab sheets.

You can follow my blog for further updation.
Happy Learning...

Friday, January 28, 2011

Signals and Systems

Here you can ask questions, give comments related to Signals and Systems.
I have uploaded my notes on the said subject.
Please check, and don't forget to give comment.
Happy Learning...

http://ifile.it/6cmf4rs