What is the charge carrier density in the conductor

In summary, the Hall voltage across a 0.800-mm-thick conductor in a 1.30 T magnetic field is 3.2 uV when the current is 12.0 A. By rearranging the equation Vh=IB/ned and plugging in the values for current, magnetic field, charge of an electron, and thickness, the charge carrier density is calculated to be 3.806*10^25 m-3. However, this answer seems unreasonable and may be incorrect due to incorrect units used for the thickness of the conductor. The correct units for thickness should be in meters, not millimeters, resulting in a new value of d = 8*10^-4 m.
  • #1
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The Hall voltage across a 0.800-mm-thick conductor in a 1.30 T magnetic field is 3.2 uV when the current is 12.0 A.

What is the charge carrier denisty in the conductor (in m-3).



I was using the equation Vh=IB/ned
where Vh is the Hall voltage
I is the current
B is the magnetic field
n is the charge-carrier density
e is the charge of an electron
and d is the thickness



I rearranged to get n=IB/Vhed
and evaluated to get 3.806*1025m-3

But this came up wrong on the assignment and it looks like an unreasonable answer. I think I need additional values but basically this entire question is really confusing me.

Thanks for the help!
 
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  • #2
Please show us what numbers you used, and try to keep everything in SI units. Because I get a different answer than you when plugging in the numbers you gave.
 
  • #3
I used the numbers I provided so:
I=12.0 A
B= 1.3 T
e= 1.6*10^(-19) C
V= 3.2*10^(-6) V
d= 0.8 mm (I left it because those are the units that the answer is in- but I'm guessing now that that is probably wrong).

What did I miss that is wrong in the calculation?
 
  • #4
The units the answer is in is meters, not millimeters. So d = 8*10^-4 m.
 
  • #5


The charge carrier density in the conductor can be calculated using the equation n = IB/Vhde, where I is the current, B is the magnetic field, Vh is the Hall voltage, d is the thickness of the conductor, and e is the charge of an electron.

In this case, we have values for I, B, Vh, and d, but we also need to know the value of e. The charge of an electron is a fundamental constant with a value of 1.602 x 10^-19 C. Without this value, we cannot accurately calculate the charge carrier density in the conductor.

I would recommend checking the given values and ensuring that all necessary information is provided before attempting to solve this problem. Without the value of e, the calculated charge carrier density will be incorrect.
 

1. What is meant by "charge carrier density"?

Charge carrier density refers to the number of charge carriers (usually electrons or holes) per unit volume in a conductor. It is a measure of how densely packed the charge carriers are within the material.

2. How is charge carrier density measured?

Charge carrier density can be measured using various techniques such as Hall effect measurements, capacitance-voltage measurements, and conductivity measurements. These techniques involve applying an electric field or voltage to the conductor and measuring the resulting current or voltage.

3. What factors affect the charge carrier density in a conductor?

The charge carrier density in a conductor is affected by factors such as the material's composition, temperature, and impurity levels. It can also be influenced by external factors such as applied electric fields or magnetic fields.

4. Why is charge carrier density important in conductors?

Charge carrier density is an important property in conductors because it determines the material's electrical conductivity. Materials with high charge carrier densities have high conductivity, making them good conductors of electricity.

5. How does charge carrier density differ in different types of conductors?

The charge carrier density can vary significantly between different types of conductors. Metals typically have high charge carrier densities due to the presence of free electrons, while semiconductors have lower charge carrier densities due to the presence of both electrons and holes. Insulators have very low charge carrier densities as they do not have any free charge carriers.

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