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trapecia [35]
3 years ago
12

Explain concept of donor levels and accepter levels in extrinsic semiconductors and How can Fermi level be defined for conductor

s , insulators and semiconductors when temperature increases above zero Kelvin.
Physics
1 answer:
nika2105 [10]3 years ago
5 0

Answer:

DONORS: If the material for which it substitutes has more electrons than the original

ACCEPTORS: If the replacement material has fewer electrons than the original material

Fermi level: the point where the probability of finding the last electron is ½

Explanation:

When in a semiconductor material a small fraction of an element is replaced by another with different valences, an excess charge is created.

If the material for which it substitutes has more electrons than the original, there is an excess of electrons, these excess electrons are weakly bound in the material and their orbits are large, in an energy versus moment diagram their energy places them a little more below the conduction band, these materials are called DONORS.

If the replacement material has fewer electrons than the original material, one electron is missing to complete the bonds, so there is a movement of the other electrons, an easier way to analyze this movement of the (n-1) electrons is to suppose that The missing charge has a positive charge and to study its movement, this positive charge is called a hole, its binding energy is small so the orbit of the hole is large, in an energy diagram it is located a little above the band of valence, these are called ACCEPTORS

The Fermi level is defined as the point where the probability of finding the last electron is ½, when the temperature is changed the density of states of the bands changes, therefore the location point moves, but its [probability remains ½

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A gyroscope flywheel of radius 1.96 cm is accelerated from rest at 13.0 rad/s2 until its angular speed is 2270 rev/min. (a) What
nika2105 [10]

Tangential acceleration of a point on the rim of the flywheel during this spin-up process is 0.2548 m/s².

Tangential acceleration is defined as the rate of change of tangential velocity of the matter in the circular path.

Given,

Radius of flywheel (r) = 1.96 cm = 0.0196m

Angular acceleration (α)= 13.0 rad/s²

The tangential acceleration formula is at=rα

where, α is the angular acceleration, and r is the radius of the circle.

using the formula; at=rα  = (13.0 rad/s²) (0.0196m) = 0.2548 m/s².

The tangential acceleration is 0.2548 m/s².

Learn more about the Tangential acceleration with the help of the following link:

brainly.com/question/15743294

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5 0
1 year ago
6. An earthquake releases two types of traveling seismic waves, called transverse and longitudinal waves. The average speed of t
zubka84 [21]

Answer:

The distance away the center of the earthquake is 1083.24 km.

Explanation:

Given that,

Speed of transverse wave = 9.1\ km/s

Speed of longitudinal wave = 5.7 km/s

Time = 71 sec

We need to calculate the distance of transverse wave

Using formula of distance

d=v\times t

d=9.1\times t....(I)

The distance of longitudinal wave

d=5.7\times (t+71)....(II)

From the first equation

t=\dfrac{d}{9.1}

Put the value of t in equation (II)

d =5.7\times(\dfrac{d}{9.1}+71)

\dfrac{9.1d-5.7d}{9.1}=71\times5.7

d0.3736=404.7

d =1083.24\ km

Hence, The distance away the center of the earthquake is 1083.24 km.

6 0
3 years ago
To summarize and analyze data with both a crosstabulation and charting, Excel typically pair
r-ruslan [8.4K]

Answer:

To summarize and analyze data with both a crosstabulation and charting, Excel typically pair  PivotCharts with PivotTables (option b)

Explanation:

Pivot Tables allows us to deal with a high volume of data. This kind of tables are mainly designed to summarize, analyze and explore data in a simple way. Meanwhile, Pivot Charts gives the possibility to visualize the summarizing data provided in PivotTables, enabling the detection of trends, correlations,comparisons and so on. Because of that Pivot tables and pivot charts are usefull and complementary tools of Excel.

Summarizing, the proper option is b.

7 0
3 years ago
What is the work energy transfer equation?
rosijanka [135]

Answer:

The equation used to calculate the work done is: work done = force × distance. W = F × d. This is when: work done (W) is measured in joules (J)

8 0
3 years ago
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Look at the variables for this lab. Which variable would we have to change in order to change the amount of current flowing thro
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Where are the variables from the lab?
3 0
2 years ago
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