This is it dont anwser this is for my other account

The electron concentration in silicon at T = 300 K is given by

puteri [66]

Answer:

$E=1.44*10^-7-2.6exp(\frac{-x}{18} )v/m$

Explanation:

From the question we are told that:

Temperature of silicon $T=300k$

Electron concentration $n(x)=10^{16}\exp (\frac{-x}{18})$

$\frac{dn}{dx}=(10^{16} *(\frac{-1}{16})\exp\frac{-x}{16})$

Electron diffusion coefficient is $Dn = 25cm^2/s \approx 2.5*10^{-3}$

Electron mobility is $\mu n = 960 cm^2/V-s \approx0.096m/V$

Electron current density $Jn = -40 A/cm^2 \approx -40*10^{4}A/m^2$

Generally the equation for the semiconductor is mathematically given by

$Jn=qb_n\frac{dn}{dx}+nq \mu E$

Therefore

$-40*10^{4}=1.6*10^{-19} *(2.5*10^{-3})*(10^{16} *(\frac{-1}{16})\exp\frac{-x}{16})+(10^{16}\exp (\frac{-x}{18}))*1.6*10^{-19}*0.096* E$

$E=\frac{-2.5*10^-^7 exp(\frac{-x}{18})+40*10^{4}}{1.536*10^-4exp(\frac{-x}{18} )}$

$E=1.44*10^-7-2.6exp(\frac{-x}{18} )v/m$

7 0

2 years ago

Can someone tell me what car year and model this is please

Arlecino [84]

Answer:

i think 1844

Explanation:

5 0

3 years ago

Read 2 more answers

A coil having resistance of 7 ohms and inductance of 31.8 mh is connected to 230v,50hz supply.calculate 1. The circuit current 2

lora16 [44]

(1) The current in the circuit is 18.87 A,

(2) The phase angle is 54.97°

(3) The power factor is 0.574

(4) The power consumed is 2491.2 W

(1) To calculate the current in the circuit, first, we need to find the overall impedance of the circuit.

We can calculate the overall impendence of the circuit using the formula below.

Z = √[R²+(2πfL)²]........................ Equation 1

Where:

R = resistance of the coil
f = Frequency
L = Inductance of the coil
Z = Overall impedance of the circuit

From the question,

Given:

R = 7 ohms
L = 31.8 mH = 0.0318 H
f = 50 Hz
π = 3.14

Substitute these values into equation 1

Z = √[7²+(2×3.14×50×0.0318)²]
Z = √(49+99.7)
Z = √(148.7)
Z = 12.19 ohms.

Therefore we use the formula below to calculate the current in the circuit.

I = V/Z.................. Equation 2

Where:

V = Voltage
I = current in the circuit.

Given:

V = 230 V.

Substitute into equation 2

I = 230/12.19
I = 18.87 A

(2) To calculate the phase angle, we use the formula below.

∅ = tan⁻¹(2πfL/R)............... Equation 3

Where:

∅ = Phase angle.

Substitute into equation 3

∅ = tan⁻¹(2×3.14×50×0.0318/7)
∅ = tan⁻¹(9.9852/7)
∅ = tan⁻¹(1.426)
∅ = 54.97°

(3) To calculate the power factor, we use the formula below.

pf = cos∅............ Equation 4

Where:

pf = power factor.

Substitute the value of ∅ into equation 4

pf = cos(54.97°)
pf = 0.574.

(4) And Finally to calculate the power consumed we use the formula below.

P = V×I×pf................ Equation 5

Where:

P = The power consumed

Substitute the values into equation 5

P = 230(18.87)(0.574)
P = 2491.22 W

Hence, (1) The current in the circuit is 18.87 A, (2) The phase angle is 54.97° (3) The power factor is 0.574 (4) The power consumed is 2491.2 W

Learn more about Impedance here: brainly.com/question/13134405

5 0

2 years ago

PLEASE ANSWEAR FAST!!! <br> What does it mean if E˂1

Citrus2011 [14]

Scientific notation is another way to write a number. In scientific notation, the letter E is used to mean "10 to the power of." For example, 1.314E+1 means 1.314 * 101 which is 13.14 . Scientific notation is merely a format used for input and output.

5 0

2 years ago

The fracture toughness of a stainless steel is 137 MPa*m12. What is the tensile impact load sustainable before fracture that a r

Charra [1.4K]

Answer:

7.7 kN

Explanation:

The capacity of a material having a crack to withstand fracture is referred to as fracture toughness.

It can be expressed by using the formula:

$K = \sigma Y \sqrt{\pi a}$