# Recent content by iampaul

1. ### I Density of States Derivation

Thanks, i've been plugging in ##\ \hbar = {h\over\pi}##.
2. ### I Density of States Derivation

I was looking for a derivation for the density of states and I came across this page: https://ecee.colorado.edu/~bart/book/book/chapter2/ch2_4.htm I followed the derivation and came up with: g(E) = (1/L3)dN/dE = (1/L3)L3/∏2*k2 * dk/dE =K2/∏2 * dk/dE =K2/∏2 * g(E) =...
3. ### Spark in relay contacts

Thank you for answering my questions. :D
4. ### Spark in relay contacts

With an inductive load, abrupt current interruption or variation induces a high voltage. I couldn't see how it can happen with a purely resistive circuit. After reading your replies, my understanding is that a spark could jump if the relay contacts are extremely close to each other, which...
5. ### Spark in relay contacts

Why is there a spark in the relay contacts? Suppose that the coil and the contacts are connected to two different power supplies. If i suddenly disconnect the power supply to the coil, then the voltage across the coil will increase and a spark will jump across the switch that I used to...
6. ### Admissions How to pay for Masters in the US

I am a US citizen. I was born in New York but I grew up in the Philippines. I am planning to take my Masters in Electrical Engineering specializing in IC design or Control Systems in the US, but when I checked the tuition/fees I learned that it would take a crazy amount of time to save up that...

Thanks for answering my questions. I have a degree in Electronics Engineering. I'll follow your advice to take up graduate school in the US. For now, I still have to work and save money to study in the US. Can I just take my MS here and take my Ph.D in the US, or would that be more difficult?

I have recently passed the Electronics Engineering Licensure exam in the philippines and I'm plannning to pursue a career in chip design preferrably mixed signal or digital. I have applied at different semiconductor companies. The problem is they don't design the IC's here, they only conduct...
9. ### Why does vacuum have resistance?

Thanks. Haha, I didn't realize that.
10. ### Why does vacuum have resistance?

Suppose that there is a positively charged particle and a negatively charged particle in free space. The electric field of the positive charge causes a difference in potential between the position of the negatively charged particle and the positively charged particle. This, causes the negatively...
11. ### Amplitude modulation and amplifier efficiency

These are sample problems from Blake's electronic comms book: 1.) A transmitter has a carrier power output of 10W at an efficiency of 70%. How much power must be supplied by the modulating amplifier for 100% modulation Book Solution: efficiency=Po/Ps (I don't know what Po is...
12. ### Amplitude modulation and amplifier efficiency

" A intelligence signal is amplified by a 80% efficient amplifier before being combined with a 12kW carrier to generate the AM signal. if it is desired to operate at 100% modulation, what is the DC input power at the modulator" The choices are a: 12kW b. 7.14kW c.7.5kW d. 15kW my solution...
13. ### How is a memristor different from a resistor

So M is not a constant unlike R, L, and C? I read that the memristor was predicted due to the symmetry of the equations for R, L and C. If M is not constant with respect to time, doesn't that make the memristor the odd one out o the four, so that there is still no symmetry?
14. ### How is a memristor different from a resistor

I read that the memristor is described by the equation dφ=Mdq. If both sides are divided by dt, then dφ/dt=Mdq/dt. But dφ/dt=V and dq/dt=I. Then V=MI which is ohm's law. Isn't the constant M just the same as resistance?
15. ### Problem with Minimum Nyquist bandwidth formula and m-ary encoding

I am using the book Electronic Communication Systems by Wayne Tomasi: I had a problem with a certain part of the book: The book gives the formula for the minimum nyquist bandwidth as: " The minimum theoretical bandwidth necessary to propagate a signal is called the minimum Nyquist bandwidth...