1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
san4es73 [151]
3 years ago
5

A cube that is 20 nanometer on an edge contains 399,500 silicon atoms, and each silicon atom has 14 electrons and 14 protons. In

the silicon we replace 4 silicon atoms with phosphorus atoms (15 electrons and 15 protons/atom), and we replace 7 silicon atoms with boron atoms (5 electrons and 5 protons/atom). How many "holes" are available to carry current at 300K? Holes look like positive mobile carriers. Three significant digits and fixed point notation.
Physics
1 answer:
Sergeu [11.5K]3 years ago
6 0

Answer:

Total 3 holes are available for conduction of current at 300K.

Explanation:

In order to develop a semiconductor, two type of impurities can be added as given below:

  1. N-type Impurities: Pentavalent impurities e.g. Phosphorous, Arsenic are added to have an additional electron in the structure. Thus a pentavalent impurity creates 1 additional electron.
  2. P-type Impurities: Trivalent impurities e.g. Boron, Aluminium are added to have a positive "hole" in the structure. Thus a trivalent impurity creates 1 hole.

Now for estimation of extra electrons in the impured structure is as

N_{electrons-free}=n_{pentavalent \, atoms}\\N_{electrons-free}=4\\

Now for estimation of "holes"  in the impured structure is as

N_{holes}=n_{trivalent \, atoms}\\N_{holes}=7\\

Now when the free electrons and "holes" are available in the structure ,the "holes" will be filled by the free electrons therefore

N_{holes-net}=N_{holes}-N_{electrons-free}\\N_{holes-net}=7-4\\N_{holes-net}=3

So total 3 "holes" are available for conduction of current at 300K.

You might be interested in
A 132 cm wire carries a current of 2.2 A. The wire is formed into a circular coil and placed in a B Field of intensity 1 T. a) F
EastWind [94]

Given Information:

Length of wire = 132 cm = 1.32 m

Magnetic field = B =  1 T

Current = 2.2 A

Required Information:

(a) Torque = τ = ?

(b) Number of turns = N = ?

Answer:

(a) Torque = 0.305 N.m

(b) Number of turns = 1

Explanation:

(a) The current carrying circular loop of wire will experience a torque given by

τ = NIABsin(θ)   eq. 1

Where N is the number of turns, I is the current in circular loop, A is the area of circular loop, B is the magnetic field and θ is angle between B and circular loop.

We know that area of circular loop is given by

A = πr²

where radius can be written as

r = L/2πN

So the area becomes

A = π(L/2πN)²

A = πL²/4π²N²

A = L²/4πN²

Substitute A into eq. 1

τ = NI(L²/4πN²)Bsin(θ)

τ = IL²Bsin(θ)/4πN

The maximum toque occurs when θ is 90°

τ = IL²Bsin(90)/4πN

τ = IL²B/4πN

torque will be maximum for N = 1

τ = (2.2*1.32²*1)/4π*1

τ = 0.305 N.m

(b) The required number of turns for maximum torque is

N = IL²B/4πτ

N = 2.2*1.32²*1)/4π*0.305

N = 1 turn

8 0
3 years ago
Below is an oscilloscope trace from an AC supply. Calculate the frequency of the supply if each horizontal division represents 0
GuDViN [60]

Answer:

20 hertz of frequency produced.

Explanation:

\boxed{frequency = \frac{1}{period} }

Here we will find frequency and period should be in second, here given: 0.05 seconds

using the formula:

\boxed{frequency = \frac{1}{0.05} }

\boxed{frequency =20}

8 0
2 years ago
a car moving with a speed of 10 metre per second is accelerator at the rate of 2 metre per second square find its velocity after
STatiana [176]

a = ( v(2) - v(1) ) ÷ ( t(2) - t(1) )

2 = ( v(2) - 10 ) ÷ ( 6 - 0 )

2 × 6 = v(2) - 10

v(2) = 12 + 10

v(2) = 22 m/s

7 0
3 years ago
The fluid pressure 10 ft underwater is _____ the fluid pressure 5 ft underwater. A.less than or greater than, depending on what
just olya [345]
<span>I would say greater than because as you do deeper, the pressure strengthens. If you were in a 10 ft deep pool and you dive all the way to the bottom, the ears usually pop. That's because of the pressure. Whereas if you were to go five feet, your ears wouldn't. It depends on the age of the person. Hope this helps.</span>
5 0
3 years ago
Describe how the earth is a "giant magnet.
Gala2k [10]
Because the core is a big ball of iron
4 0
3 years ago
Other questions:
  • The phrase all men are created equal is from what document
    6·1 answer
  • A 54-kg ice skater pushes off the wall of the rink, giving herself an initial speed of 3.5 m/s . She then coasts with no further
    7·1 answer
  • Which of the following is an example of sustainable use of natural resources? Question 21 options: 1) clear-cutting a forest 2)
    10·2 answers
  • The fastest propeller-driven aircraft is the Russian TU-95/142, which canreach a maximum speed of 925 km/h. For this speed, calc
    12·1 answer
  • Name and describe three measures of central tendency used to summarize data.
    6·1 answer
  • A child bounces a 51 g superball on the sidewalk. The velocity change of the super bowl is from 22 m/s downward to 14 m/s upward
    7·1 answer
  • As a delivery truck travels along a level stretch of road with constant speed, most of the power developed by the engine is used
    11·1 answer
  • Please I need help its timed-
    13·2 answers
  • Please help! i will give brainliest :)
    6·1 answer
  • True or false. A separation technique that can be used for this investigation is centrifugation.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!