1 : i am student of ece in 7th sem .plz suggest some effective topic(technical) for seminar ...
I have stated this quite a few times before, and I will say this again sir, that topic should be of your choice. Not of a creepy-good-for-nothing-ugly-faced-monster's suggestion from other side of internet. ( refering to myself just for record)
What could we say????
But still if you ask - everyone here talks about mechatronics as a beautiful topic, nano electronics, and MEMS included in it. If you study mems in details for instance, and show some real findings of some calculations in your seminar that would be awsome, and dude SO WOULD BE ANY OTHER TOPIC.
This is a general formula. Even if you pick AC power coming to your house and want to talk about that in seminar, its a "GREAT TOPIC".
1. How does it affect general communications?
2. How can it be used to transmit data?
3. How can AC be bad for health of heart patients on wireless meters inside their bodies?
4. What about trasmitting AC wirelesslessly??? Pros and Cons? How can be mass production achieved?
etc
etc
etc
I could talk about same about "water tap" or Self assembly DNA circuits. Does not matter.
You get the idea I know.
Seminar's generic fundamental is :
1. Pick a topic that you love love love
2. Study hard about that, know everything about everything in that topic
3. try to do some "original work" of your own some data analysis, some future work direction. How can you improve this work?
4. Make very neat, flowing presentation. If you can arrange a computer projector to illustrate simulations in real time, that would be awsome, otherwise ppt would be just fine.
5. If possible, give a neat copy to evaluators, and be sure to rehearse and look at audience when you talk. Seminar is 25% research work and content, 75% your presentation style. Thats primarily why they make you do these things.
Hope that helps If not ask again. Will try to be precise and to the point, unlike this time.
2.what happen when we apply a ramp input to the capacitor i tried to search this question in many books & think over a lot .. but couldnt got any answer... in some books they have treated it mathematically but no one have given any intutive explanation .
as we found that when a instantaneous voltage is applied at capacitor.....it acts as a virtual short ..... but what could be the intutive xplanation for this........
this will limit the current! which is directly proportional to the rate of change of voltages! and also Rate of charging of the Capacitor ie., Capacitance and load Resistance!
let Vs be the source ramp input! while Vc be the voltage across the capacitor
when Vs=x1 initially then the capacitor would behave like the Short Circuit! and would tend to be open circuit i.e., Vc->Vs=x1 this depends upon the t, the charging time!
ideally if t=0; then at Vs=x2; Vc=x1; Thus the Net Minimum Potential Difference would be Vsc=(x2-x1)/R ; Where R is Constant! Thus Current would be limited by The difference of x2-x1.
The More the tau the more will be the difference! The greater will Current Follow!
3.same what will happen when we apply a sinusoidal input to the high pass Rc ckt .... we know that the output waveform will be a sinusoid ...but is there any intutive explanation of this question too...
It depends upon the frequency of sinusoidal and the Cutt-off frequency of the filter!
if Sinusoidal Frequency is lesser than the Pass Band then offcourse it will be supressed!
if it is greater then it will pass through!
if the sinsusoidal is not Pure but contains harmonics! then the lower harmonic component will be supressed by the filter.
we are treating as a phase shift occurs but why the phase shift is occuring from ckts point of view ..... intutive xplanation...........
Phase shift is because of Charging time tau!
Vs=Vc exp^(-t/tau)
as it has already been mentioned above! the voltage across the capacitor will tend to build Vs i.e., Applied voltage across it as everything tends to acquire the state of equilibrium! and this behaviour is dependent upon tau! offcourse!
correction:
Vs=Vc*exp(-t/tau) is the discharging time
Vs=Vc(1-exp(-t/tau)) is the charing time of the capacitor