Yup, V =Q/C , and f=1/(2∏RC)
But why is this the Bandwidth? The impedance of capacitor is same as resistance so we get maximum power for?
And 10000 electrons need to consider shot noise? If I consider, so I just add thermal noise voltage and shot noise together to get the total voltage noise?
Homework Statement
The output of a sensor which produces 10000 electrons is connected to parallel RC circuit with Resistance= 50 ohm, and the capacitance=10pF.
Calculate the signal to noise ratio at temperature 300K.
Homework Equations
SNR= 10 log (power of signal/ power of noise)
Or...
##\vec{L}^2## mean the angular momentum square
##L_z## angular momentum in z direction
##\vec{L}^2##=l(l+1)\hbar and ##L_z##=m\hbar.
Total orbit angular momentum is j?
J=l-(1/2) or l+(1/2)
Homework Statement
A hydrogen atom is identified as being in a state with n=4. What is the magnitude of the total orbital angular momentum for the largest permitted value of l?
Homework Equations
n>l, l is bigger or equal to m
The Attempt at a Solution
The allowed l= 3,2,1
The allowed m for...
Thank you. If I want to calculate the output impedance, I have to off the input signal, yet there are still 2 dc supplies ,one to gate-source, another is the $V_cc$ , and there should be current pass though , but my book said $g_mV_{gs}$ =0?
From the picture you gave,
BJT ,the output voltage is amplified because there is dc voltage supply to keep BJT active ,but what about the FET? The voltage supplied only control the gate only, anything to do with the output?
Thanks
To encode a symbol in binary form, I need 3 bits ,and I have 6 symbols.
So I need 6*3=18 bits to encode "We are" into binary form. As shown in http://www.shannonentropy.netmark.pl/calculate
My question: 3 bits to encode one then I have to use 16 bits, _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
How to...
The following is the Planck's derivation for black body radiation
$${\rho}({\lambda}) d{\lambda}=E({\lambda})*f({E(\lambda}))*D({\lambda})d{\lambda}------equation 1$$
$$\int_0^\infty{\rho}({\lambda})d{\lambda}$$ is the density of radiative energy.
From...
Can you please explain more? How two taps to empty a water tank? Water go from taps to tank then?
How should I prove the two polarization modes? Please tell me. Thanks.
$${\rho}({\lambda}) d{\lambda}=E({\lambda})*f({E(\lambda}))*D({\lambda})d{\lambda}$$
$${\rho}({\lambda}) d{\lambda}$$ is density of radiative energy,
$$E({\lambda})= k_BT$$ is the energy of an atom vibrate in 3D,
$$f({E(\lambda}))=1$$ is the probability distribution. Equals to 1 because we...
Dulong Petit use energy,E=$k_B$T and the probability distribution as f(E)=1.
Internal energy,u=3N$k_B$T
$$C_v=∂u/∂T=3NkT$$
Three there because there is 3 modes in each atom.
Then my question is why do we use E=kT?
I understand 1 atom has 3 degree of freedom,and 1 freedom has kT/2.
A...
Sorry, it is spectrometer.
Yup it is use to find the refractive index of the glass cell.
My book says : a sharp boundary distinguishes the bright from the dark region because no rays are refracted with an angle of refraction larger than critical angle.
So ? I think the refraction will occur...
Refractive index----- will it travel back along the same way?
From the picture
http://en.wikipedia.org/wiki/File:RefractionReflextion.svg
If I travel a light ray from n2 to n1 , I think the light ray will travel in the opposite direction shown in the first picture.
But what about the...
I am sorry, but I am still confused.
No need to keep E constant, because the interception point I want is $${\u_o}$$ (from Wikipedia ) . But I still wonder how to find out the minimum voltage? $$ {u_ o} < {\frac{\pi}{2}}$$ then solve for minimum V.
Thanks for replying. So my answer is (-pa/z)< (pi /2), by keeping the energy constant and the solve for the minimum V.
One more to ask, actually what does it mean no bound state ? I wonder what is the physical meaning of no bound state? No wave function?
Homework Statement
Show in the graph ,there will be no allowed bound states with odd-parity if the well depth is less than ${V_min}$
Find ${V_min}$ in terms of k and a.where a is the half of the well width.
What does no allowed bound state mean?
Homework Equations
$cotz=-pa/z$ where p^2...
The exponential function ( is not complex ) here doesn't represent wave that is why no wave outside the well.
But why do we have exponential function outside the well? What does it represent?
Thanks
Yup, it is scattering state. So it doesn't mean we don't have wave from the right, we take only left for simplicity.
Reflected means bounce back, but in this scattering state, there is no potential wall or any wall, why the wave bounce back?