Logarithm Help

[Corbeau_dubh]

Any help with this would be greatly appreciated. I'm in the dark at the moment.

In an electrical circuit, the voltage, ?, across a diode and the current, ?, through it are related by

?=??(?11600?/??−1)

where:
?? is the reverse saturation current
? is (eta) the emission coefficient, and
? is absolute temperature.

Make ?the subject of the formula, and evaluate ? for ?=2; ?=330?; ??=0.1??; and ?=5??.

Convert currents to scientific notation before calculating voltage resultant

 

[skeeter]

assuming [MATH]i = I_s \left(e^{\frac{11600v}{\eta T - 1}}\right)[/MATH]
1. divide both sides by [MATH] I_s[/MATH]
2. take the natural log of both sides

3. solve for [MATH]v[/MATH]

 

[Corbeau_dubh]

assuming [MATH]i = I_s \left(e^{\frac{11600v}{\eta T - 1}}\right)[/MATH]
1. divide both sides by [MATH] I_s[/MATH]
2. take the natural log of both sides

3. solve for [MATH]v[/MATH]

Thank you for your help. It's much appreciated. I'm new to logs so I'm probably wrong put the next line would be

i-?? = ?11600?/??−1

 

[tkhunny]

Thank you for your help. It's much appreciated. I'm new to logs so I'm probably wrong put the next line would be

i-?? = ?11600?/??−1

Doesn't look like anything happened. The point of introducing the logarithm is getting rid of the exponential.

BTW:

1) e11600? is NOT [math]e^{11600\nu}[/math]
2) ?/??−1 is NOT [math]\dfrac{\nu}{\eta t - 1}[/math]

 

[skeeter]

use grouping symbols to make your original equation clear to those reading it ...

? = ?? * ?^[(11600?)/(??−1)]

Thank you for your help. It's much appreciated. I'm new to logs so I'm probably wrong put the next line would be

i-?? = ?11600?/??−1

divide, not subtract ...

[MATH]\dfrac{i}{I_s} = e^{\frac{11600v}{\eta T-1}}[/MATH]
now take the natural log of both sides

 

[tkhunny]

Also, BTW

When the assignment is "Solve for [math]\nu[/math]", you may not include a step described as "Solve for [math]\nu[/math]".

 

[skeeter]

Also, BTW

When the assignment is "Solve for [math]\nu[/math]", you may not include a step described as "Solve for [math]\nu[/math]".

ok, how about ...

3. "algebraically isolate [math]\nu[/math]"

... does that meet with your approval?

 

[Corbeau_dubh]

ok, how about ...

3. "algebraically isolate [math]\nu[/math]"

... does that meet with your approval?

Hello. I've just quoted it from a text book.
I'm learning as I go, so I'm somewhat slow at the process.

 

[Corbeau_dubh]

use grouping symbols to make your original equation clear to those reading it ...

? = ?? * ?^[(11600?)/(??−1)]



divide, not subtract ...

[MATH]\dfrac{i}{I_s} = e^{\frac{11600v}{\eta T-1}}[/MATH]
now take the natural log of both sides

Thank you, I'll try it now.

 

[tkhunny]

ok, how about ...

3. "algebraically isolate [math]\nu[/math]"

... does that meet with your approval?

Not a matter of approval. Restating the problem does not ever constitute a solution.