Explain concept of donor levels and accepter levels in extrinsic semiconductors and How can Fermi level be defined for conductors , insulators and semiconductors when temperature increases above zero Kelvin.
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
Scientists today use satellites as well as telescopes to observe the universe. Suggest one way
that developments in equipment have changed the information scientists collect about
planets.
Answer:
Rovers, unmanned space probes, modern instruments,
Explanation:
31) A box is pushed, up a ramp, at constant velocity with a force of 14 N.
What is the magnitude of the friction force working on the box? *
The magnitude of the frictional force working on the box is 14 N.
According to Newtons's first law, an object will continue in its state of rest or state of uniform motion unless it is acted upon by an unbalanced force. This means that motion or acceleration is caused by an unbalanced force.
Since the box is moving at constant velocity, the frictional force on the box and the force that moves the box forward are exactly equal in magnitude but opposite in direction.
Learn more: https://brainly.com/question/9352088?
Calculate the force that is applied on this 0.25 kg ball, as it goes down to hit the ground.
(given gravity= 9.8 m/s2).
Answer:
F = 2.45 N
Explanation:
m = 0.25 kg
a = 9.8 m/s^2
F = ma
F = (0.25)(9.8)
F = 2.45 N
Derive the relation between wavelength, frequency and speed of sound.
Explanation:
sorry I need some points foe this
During the Egg Drop lab sim you manipulated several variables like height, egg mass and impact surface. If you dropped a large egg from 10 meters which one condition would allow the best chance for the egg to survive unbroken?
Answer:
An egg with a thick shell.
Explanation:
Hope this helps.
Explique cómo es que las estrellas emiten una radiación, específicamente qué es lo que sucede a nivel atómico
Answer:
Las estrellas se forman debido a la unión de pequeños elementos y partículas como el hidrógeno y el helio que experimentan una fusión nuclear en el núcleo debido a la intensa presión para formar un nuevo átomo (como dos hidrógeno que se combinan para formar un átomo de helio) que es un proceso. que requiere una gran cantidad de energía para comenzar, por lo que cada reacción de fusión produce una gran cantidad de energía que puede mantener la reacción y equilibra la fuerza gravitacional que atrae las masas de las partículas hacia el centro de la estrella
A medida que la energía de la estrella se irradia, la superficie de la estrella cede la energía en forma de calor y luz de manera que debido a la alta temperatura de las partículas de los átomos de los elementos se mueven muy rápida y energéticamente para emitir fotones rápidamente. (alta frecuencia) que se ve como el alto brillo de la estrella
Explanation:
Do only number 3 and thank
Charge = 0.2 Ah is the correct answer...
HELP ME PLEAASSEEE ILL MARK U THE BRAINLIEST
Answer:
Gravitational energy and kinetic energy
HELP ME ILL MARK U THE BRAINLIEST
the crane takes 2.5s to raise the box 3.0 m. Calculate the power output of the crane
Answer:
Power = 1800 W
Explanation:
Power = work / time
Power = 4500 / 2.5
Power = 1800 W
To clean the floor, David exerts a 40 N force on a broom handle to push it 2 m. If the broom handle makes a 40° angle with the floor, what is the work done by David on the broom? If the broom handle were angled at 65° would David do more or less work? Explain your answer. Use the Guess method.
Answer:
Explanation:
Work done = Force * Displacement
There is no displacement vertical so only the horizontal part of force did work.
The horizontal force = Force * cos(angle with floor)
Work done = 40*cos(40°)*2
= 61.28 J
As cos(65°) is less than cos(40°), work done will be less at 65°.
Craig is modeling the discovery of electromagnetism. Which procedure should he use?
A. moving a magnet into a coil of wire in a closed circuit
B. moving a magnet into a coil of wire in an open circuit
C. bringing a compass near a wire that has no electric current
D. bringing a compass near a wire that has an electric current
Answer:
A
Explanation:
moving a magnet into a coil of wire in a closed circuit
Craig, move a magnet into a coil of wire in a closed circuit for the discovery of electromagnetism. Option A is correct.
What is electromagnetism ?The physical interplay of electric charges, magnetic moments, and the electromagnetic field is known as electromagnetism.
The electromagnetic field can be static, moving slowly, or forming waves.
Craig, move a magnet into a coil of wire in a closed circuit for the discovery of electromagnetism.
Hence, option A is correct.
To learn more about the electromagnetism, refer to the link;
https://brainly.com/question/3427992
#SPJ2
You can do only number 1 only
For 1000 seconds , a current of 0.1 A flows so as to transfer charge of 100C
A meterstick is placed on a pivot point of 42.5cm and a 45g mass is hung at the 20cm mark. When released the meterstick remains in static equilibrium. What is the mass of the meterstick
Write the formula of gravitational force between two bodies of masses x and y kept at a distance r
Answer:
F=Gxy/r^2
Explanation:
F=Gm1m2/d^2
F=Gxy/r^2
what is the momentum of an object weighing 7.5 kg moving at 1.6 m/s?
Answer:
[tex]momentum = mass \times velocity \\ = 7.5 \times 1.6 \\ = 12 \: kg {ms}^{ - 1} [/tex]
Mass is 7.5 kg
Velocity is 1.6 m/s
we know that,
momentum = mass × velocity
or; momentum =7. 5 kg × 1. 6 m/s
or; momentum = 12 kgms^1
How much power is required to do 180 J of work in 2.4s?
The power required to do 180 J of work in 2.4 s is 75 W.
What is power?Power can be defined as the rate at which work is done.
To calculate the power, we use the formula below
Formula:
P = E/t............. Equation 1Where:
P = PowerE = Energy or workt = Time.From the question,
Given:
E = 180 Jt = 2.4 sSubstitute these values into equation 1
P = 180/2.4P = 75 W.Hence, the power required to do 180 J of work in 2.4 s is 75 W.
Learn more about power here: https://brainly.com/question/24858512
#SPJ2
How are galaxies named?
Answer:
Some galaxies are given descriptive names (e.g. "Andromeda", "Whirlpool") if they are particularly distinctive in location or appearance. But most galaxies are known from their designation in a catalogue. One of the earliest catalogues of objects in the sky was made by Charles Messier.
A 1.50 kg ball moving at 4.50 m/s is caught by a 60.0 kg man while the man is standing on ice. How fast will the man / ball combination be moving after the ball is caught by the man?
Answer:
Explanation:
The Law of Momentum Conservation applies, and the formula for us here specific to this problem is:
[tex][(m_bv_b)+(m_mv_m)]_b=[(m_b+m_m)v_{both}]_a[/tex] and filling in:
[(1.50*4.50)+60.0*0)] = [(1.50 + 60.0)v] and
6.75 + 0 = 61.5v so
v = .110 m/s in the same direction as the ball
an object of volume 1m3 and density of 500kg/m3 float in water what volume of water is displaced
Answer:
[tex]0.5\; \rm m^{3}[/tex].
Explanation:
Calculate the mass of this object:
[tex]\begin{aligned}& m(\text{object}) \\ &= \rho(\text{object}) \cdot V(\text{object}) \\ &= 500\; \rm kg \cdot m^{-3} \times 1\; \rm m^{3} = 500\; \rm kg\end{aligned}[/tex].
Multiple the mass of this object by the gravitational field strength, [tex]g[/tex], to find the weight of this object: [tex]W(\text{object}) = m(\text{object}) \cdot g[/tex].
Since this object is floating in water, the buoyancy force on it should be equal to its weight:
[tex]F(\text{buoyancy}) = W(\text{object}) = m(\text{object}) \cdot g[/tex].
By Archimedes' Principle, the weight of the water that this object displaces would be equal to [tex]F(\text{buoyancy})[/tex], the size of buoyancy force on this object,
Hence, the weight of water displaced would be [tex]W(\text{object}) = m(\text{object}) \cdot g[/tex].
Divide this weight by [tex]g[/tex] to find the mass of water displaced:
[tex]\begin{aligned} & m(\text{water displaced}) \\ &= \frac{W(\text{water displaced})}{g} \\ &= \frac{m(\text{object}) \cdot g}{g} = m(\text{object}) = 500\; \rm kg\end{aligned}[/tex].
Assume that the density of water is [tex]\rho(\text{water}) = 1000\; \rm kg \cdot m^{-3}[/tex]. The volume of water displaced would be:
[tex]\begin{aligned}& V(\text{water displaced}) \\ &= \frac{m(\text{water displaced})}{\rho(\text{water})} \\ &= \frac{500\; \rm kg}{1000\; \rm kg \cdot m^{-3}} = 0.5\; \rm m^{3}\end{aligned}[/tex].
What is the value of x in the triangle? a 45-45-90 triangle with leg length x and hypotenuse length 4
Answer:
[tex]x = 2\sqrt 2[/tex]
Explanation:
Given
[tex]Hypotenuse = 4[/tex]
Required
Find x
Since the triangle is a 45-45-90 triangle, the following relationship exists
[tex]x^2 + x^2 = 4^2[/tex] --- i.e. the other legs are equal
So, we have:
[tex]2x^2 = 16[/tex]
Divide both sides by 2
[tex]x^2=8[/tex]
Take square roots of both sides
[tex]x = \sqrt 8[/tex]
Simplify
[tex]x = 2\sqrt 2[/tex]
Answer:
7√2
Explanation:
A cubic box has a 0.8 meter side. Find the volume of air in the box in cubic meter?
Answer:
[tex]V=0.512\ m^3[/tex]
Explanation:
Given that,
The side of a cubic box, s = 0.8 m
We need to find the volume of air in the box.
We know that,
The volume of a cube is given by :
[tex]V=s^3[/tex]
So,
[tex]V=0.8^3\\\\V=0.8\times 0.8\times 0.8\\\\=0.512\ m^3[/tex]
So, the volume of air in the box is [tex]0.512\ m^3[/tex].
if you can't test an explanation through experiment,
A) the phenomena let's not have occurred in the physical world
B) people will disagree on whether the explanation is correct
C) your observation must not have really occurred
D) a group of scientists will vote on their favorite explanation
Answer:
B
Explanation:
An ohmic dipole of resistance 100 ohm is crossed by a current of intensity 120 ma. Calculates the voltage across this chemical dipole
Answer:
12.0 Volt
Explanation:
Step 1: Given data
Resistance of the ohmic dipole (R): 100 Ohm
Intensity of current (I): 120 mA (0.120 A)
Step 2: Calculate the voltage (V) across this chemical dipole
To calculate the voltage across the ohmic dipole, we will use Ohm's law.
I = V/R
V = I × R
V = 0.120 A × 100 Ohm = 12.0 V
A 5L container has a
Answer:a gas at pressure of 0.8 m column of H g
Explanation:I thinkfor the light bulb to produce the aame illuminace with the candle to the screen, the luminous intensity of the bulb is _______ that of the candle?
Answer:
9 times
Explanation:
luminosity decreases to the square of the distance
convert 3 hours 30 minutes into second
Answer:
9000 SECONDS
Explanation:3 hours=180 mins
180+30=210mins
150x60=12600secs
The absorption of a photon causes a hydrogen atom
to change from the n = 2 to the n = 3 energy state.
What is the energy of the absorbed photon?
A) 4.9 eV
C) 1.9 eV
B) 3.4 eV
D) 10.2 eV
4.9 eV is the correct answer
Hope it helps you ^ _ ^
A jetliner can fly 8.0 hours on a full load of fuel. Without any wind it flies at a speed of 2.42 x 102 m/s. The plane is to make a round-trip by heading due west for a certain distance, turning around, and then heading due east for the return trip. During the entire flight, however, the plane encounters a 40.7-m/s wind from the jet stream, which blows from west to east. What is the maximum distance (in kilometers) that the plane can travel due west and just be able to return home
Answer:
3386.23 Km
Explanation:
Without any wind interference the speed of the plane, it flies at 2.42 x 102 m/s or 242 m/s
The magnitude of the velocity of the air = 40.7-m/s
The time taken, for the plane to fly due west, tw = distance, x ÷ (speed of the plane without wind interference, up - the magnitude of the velocity of the air, ua).......... (equation 1)
The time taken, for the plane to fly due east, te = distance, x ÷ (speed of the plane without wind interference, up + the magnitude of the velocity of the air, ua).......... (equation 2)
To calculate the total time, t, the plane can fly to cover east and west distances, we add equation 1 and 2 together
t = (x ÷ (up - ua)) + (x ÷ (up + ua))
Making distance x, the subject of the formula we have:
x = t ( up²- ua²) ÷ 2up
note t = 8.0 hours which is (8 x 60 x 60) seconds = 28,800
So, x = 28,800 ((242 m/s)² - (40.7-m/s)²)÷ 2(242 m/s)
x= 1,638,936,288 ÷ 484
= 3386.23 Km
A man who weighs 75kg on the surface of the earth whose mass is 6*10^24kg. If the radius of earth is 6480km ,calculate the force of attraction between them.
Answer:
718.02N is the answer to the question