Some Physics questions (1 Viewer)

[louanna]

Is there anyone can help me to explain the followiny queations? Please~~~


how do we make transistors, microchips and micro processors? What did they replace and why?

Describe all the parts of the graph that we use in the Planck's constant experiment.


Metals have a crystal lattice structure.In terms of this, explain BSC theory.


what are cathode rays?

 

[Forbidden.]

how do we make transistors, microchips and micro processors? What did they replace and why?

Transistors, microchips and microprocessors are made from doped Group 4 elements such as Silicon or Germanium which changes its electrical properties by manipulating the number of free electrons in the orbit of each atom in the lattice structure (which must be extremely pure) of the above mentioned devices.

Describe all the parts of the graph that we use in the Planck's constant experiment.

The equation depicted on the graph of the experiment to determine Planck's constant is given by:

E = hf - W = hf - hf₀

Where W is the work function and f₀ is the threshold frequency.
In your experiment you will probably test each different metals for the photoelectric effect.

E is the dependent variable which is the maximum kinetic energy of the electron it possessed when all (none, never in between) of a photon's energy is transferred to it (provided it overcomes the threshold frequency first).
(Electrons emitted a.k.a. photoelectrons will only be emitted if E > 0)

h is Planck's constant, if you performed your experiment carefully the value should be around 6.626 x 10^-34 J.s
Since this is a constant it takes the form of a gradient on the graph, you will notice why regardless of what metal you use, every line you plot seems to be slanting at the same angle'

f is the frequency of the incoming photon of light.
You will vary this in the experiment.

f₀ is the threshold frequency of the metal, which is the mimimum frequency required from the incoming photon to begin removing electrons off the surface of a metal.

The work function (W) is the product of the Planck's constant and the threshold frequency of the metal (not the photon's frequency) and can be found via the y-intercept (When it crosses the vertical axis of the graph)

This is similar to the equation you encountered in Year 9 to 11, y = mx + b, where m is the gradient (like Planck's constant) and x is the variable (like the frequency of incoming photons) and b is the y-intercept (like the work function).

Metals have a crystal lattice structure.In terms of this, explain BSC theory.

It's BCS theory not BCS, although you don't need to know what BCS stands for.
The crystal lattice structure is not necessarily explained by the BCS theory.
The technique that demonstrated that metals had a crystal lattice structure was called diffraction.
Electromagnetic rays of very high frequencies (therefore highly penetrating) such as X-rays reflect off the individual atoms in the lattice at a certain angle and onto a film, allowing physicists to examine the internal geometry of the metal.

The BCS theory is a quantum mechanical phenomenon which only takes place when a superconductor is below its critical temperature.

Despite the fact electrons repel each other by nature, under this phenomenon electrons actually join up and are called Cooper pairs and travel through the positive lattice of the superconductor and attract them through phonons which propagate alongside the Cooper pairs through the positive lattice.

what are cathode rays?

Cathode rays are simply electrons emitted using a high potential difference from the cathode to the anode in low pressure and/or vacuum tubes called cathode ray tubes.
They are subject to deflection by magnetic fields and electric fields and exhibit both wave (travels in a straight line) and particle properties (possesses energy and momentum).

 

[me121]

Transistors, microchips and microprocessors...

Microchips and microprocessors are made up of gates.
gates are made up of transistors.