# Search results for query: *

1. ### Amplitude modulation equation

In the amplitude modulation equation, V=(Ec+Ei*coswt)coswt I don't understand why the instantaneous value of information signal is used. Shouldnt it be peak value as that would give the maximum value (amplitude)?
2. ### KWhr to kW?

If an engine that requires 3kW to run exists... How many units of electricity will it consume in an hour... (1kWhr=1unit). I cannot get my head around this. I am new to this topic and with no one around to help me. This might be very basic to you all but i am just a kid. Sorry about that...
3. ### [beginner] Network coverage inside an elevator?

So many telecom operators claim that their users will get network coverage even inside an elevator. But according to Gauss' theorem, no charge is supposed to exist inside a closed conductor and an elevator (made of metal) is a closed conductor... So how is one supposed to get network coverage...
4. ### [beginner] Current in a capacitive circuit

tell me if i am right through an inductor when AC current flows... because of ampere's law magnetic field is created... but since the current is always changing, the magnetic field is always changing... now due to faraday's law... the changing magnetic field causes a emf... but according the...
5. ### [beginner] Current in a capacitive circuit

yeah i know about the inductor a little... it stores electrical energy in terms of magnetic field... yes i know what back emf is... it is the emf that opposes the applied emf due to self inductance? i had also mentioned about whether back emf is the cause of current lagging before...
6. ### [beginner] Current in a capacitive circuit

in an inductor... with time current will increase and voltage will decrease? so the current-time graph of the capacitor will look like the voltage-time graph of the inductor?
7. ### Integrating (x2-5)1/2: Step-by-Step Guide

hey... i am new to integration so am not that good at it... i got it with your method and hint.. thanks !
8. ### Integrating (x2-5)1/2: Step-by-Step Guide

sorry i had made a mistake... i forgot the root sign... but i think this time i got it correct.. could you please check it for me... PS: moderators... i m not posting the solution... i am actually checking if what I've done is correct... http://img831.imageshack.us/i/p1010910lr.jpg/
9. ### Integrating (x2-5)1/2: Step-by-Step Guide

yeah now 5 \int tan\theta tan\theta sec\theta d\theta put t = sec\theta therefore dt = sec\theta tan\theta d\theta draw a right angled triangle... using t = sec\theta.. you'll get value of two sides... find the value of the third side by pythagoras theorem... that way now you can find...
10. ### [beginner] Current in a capacitive circuit

hey studiot... thanks a lot... the graphs helped hey berkeman... thanks a lot to you too... there is no confusion now about the capacitor, i have a clear idea now... thanks to you both! FOR INDUCTIVE CIRCUIT: I must always be a sine wave... therefore e will be cosine wave... thus i lags...
11. ### Integrating (x2-5)1/2: Step-by-Step Guide

use x = root5 sectheta... i've solved it...works like a dream!...
12. ### [beginner] Current in a capacitive circuit

yeah i get that they are proportional... what i don't understand is how does current proportional to change in voltage and voltage proportional to change in current suggest whether current lags or leads... kindly elaborate... i kinda understood what studiot said about capacitors... can a...
13. ### [beginner] Current in a capacitive circuit

thanks!.. now just to summarize... tell me if I'm right.. In a capacitive circuit, for a small change in voltage, there is a large change in current... so current is always more in the circuit... thus current is always leading the voltage for a inductor, a small change in current results in...
14. ### [beginner] Current in a capacitive circuit

@berkeman yeah that did help a lot i was familiar with the differential equation for inductance.. just didnt know that it is called that however could you temme how do you get that differential equation for capacitance? please!

thank u!
16. ### Infinite mass and light speed

hmm... thank you for clearing it out! what is 0/0 anyway? not defined?
17. ### [beginner] Current in a capacitive circuit

@studiot totally helped.. thanks a ton... but i'd like to see those curves... want to see if they are like how i imagine them to be... Could you also explain with that simplicity why current would lag behind the emf in an inductive circuit?... that'll help a lot sorting out my confusion about...
18. ### [beginner] Current in a capacitive circuit

no i haven't seen those curves i have a rough idea of what happens when capacitor is connected to DC circuit... temme if m correct.. When DC is applied to capacitive circuit, current flows for a very short time till the capacitor is filled and then there is no current in the circuit as the...
19. ### Infinite mass and light speed

yeah that is the rest mass... and light is never at rest so isn't talking about the other mass a little more practical? and 0/0 still is infinite right? so the other mass is infinite... doesnt that mean that when light falls on me... i should be blown (no pun intended)? PS: as you can judge by...
20. ### [beginner] Current in a capacitive circuit

Hey people!.. this is what I've been wondering for a while and couldn't come up with anything (asked my frnds too) It has been derived in my textbook that when AC is applied to a pure capacitive circuit (i.e. contains only a capacitor)... current leads ahead of the emf by phase difference of...
21. ### Infinite mass and light speed

m_{SR}=\frac{m_{0}}{\sqrt{1-\frac{v^{2}}{c^{2}}}} according to this formula... anything that travels with speed of light will have infinite mass... but light also travels like a matter... and so light(matter) obviously travels at the speed of light... doesn't it imply that light(as a...
22. ### Understanding EMF, Potential Difference & Current Flow

hmm.. that helped.. thanks!
23. ### Understanding EMF, Potential Difference & Current Flow

'it is emf when no current is flowing outside the cell. Whereas, it is potential difference is when current actually flows out of the cell." "that emf is the potential difference when there is no current flowing through the circuit or when the key is open. Whereas, the circuit has certain...
24. ### Centripetal force with circular motion

maximum tension is the tension at the lowest point and tension at the lowest point = mv2/r + mg works to around 61.72 by taking g = 9.8m/s