Complete the sentence to explain when waves interact.

Find the current that flows in a silicon bar of 10-μm length having a 5-μm × 4-μm cross-section and having free-electron and hol

alexdok [17]

Explanation :

It is given that,

Length of silicon bar, $l=10\mu m= 0.001\ cm$

Free electron density, $n_e=104\ cm^3$

Hole density, $n_h=1016\ cm^3$

$\mu_n=1200\ cm^2/Vs$

$\mu_p=500\ cm^2/Vs$

The total current flowing in bar is the sum of drift current due to hole and the electrons.

$J=J_e+J_h$

$J=nqE\mu_n+pqE\mu_p$

where, n and p are electron and hole densities.

$J=Eq[n\mu_n+p\mu_p]$

we know that $E=\dfrac{V}{l}$

So, $J=\dfrac{V}{l}q[n\mu_n+p\mu_p]$

$J=\dfrac{1.6\times 10^{-19}\ C}{0.001\ V}[104\ cm^{-3}\times 1200\ cm^2/V\ s+1016\ cm^{-3}\times 500\ cm^2/V\ s]$

$J=1012480\times 10^{-16}\ A/m^2$

or

$J=1.01\times 10^{-9}\ A/m^2$

Current, $I=JA$

A is the area of bar, $A= 20\mu m=0.002\ cm$

So, $I=1.01\times 10^{-9}\ A/m^2\times 0.002\ m^2$

Current, $I=2.02\times 10^{-12}\ A$

<em>So, the current flowing in silicon bar is </em> $I=2.02\times 10^{-12}\ A$ .

7 0

4 years ago

When a basketball player jumps to make a shot, once the feet are off

In-s [12.5K]

There's no question.I think these are just the answer choices

3 0

3 years ago

How much heat energy is needed to raise the temperature of 2.0 kg of concrete from 10c to 30c

kompoz [17]

50 because read step by step explanation

3 0

3 years ago

A 90-g bead is attached to the end of a 60-cm length of massless string. The other end of the string is held at point O, which i

Gekata [30.6K]

Hope this helps you.

4 0

4 years ago

A car slams on the brakes to stop. The road pushes back up on the car with a normal force of 12,750 N and friction from the brak

ivann1987 [24]

Answer:

$\displaystyle \mu_d=0.75$

Explanation:

Coefficients of Friction

Objects in physical contact produce friction which usually manifests as thermal energy being dissipated in the surface where the objects are interacting. It's usually harder to start to move an object from rest, that keeps moving it at a constant speed on the same surface. That is why there are two different coefficients of friction: the static and the dynamic. As mentioned, the static coefficient $\mu_s$ is greater than the dynamic coefficient $\mu_d$ . The car is already moving and is attempting to stop. The coefficient of friction is defined as

$\displaystyle \mu_d=\frac{F_r}{N}$

Where Fr is the force of friction and N is the normal or the force the road pushes back up on the car. With the given data, we have

$\displaystyle \mu_d=\frac{9,560\ N}{12,750\ N}$

$\displaystyle \boxed{\mu_d=0.75}$

The coefficient of friction is dimensionless (doesn't have any units)

6 0

3 years ago