Finding resistane and current non-ohmic

• Eagle's Wings
R.In summary, the problem involves a 10.0-μF capacitor charged by a 10.0-V battery through a resistance R, reaching a potential difference of 4.00 V at 3.00 seconds after charging begins. The equation i=\frac{dq}{dt}=-\frac{CV_{ab}}{RC}e^{-t/RC} can be used to find the current at t=3.00 seconds after charging begins. To find R, you need to find the time constant RC and use the given information about C.
Eagle's Wings

Homework Statement

A 10.0-μF capacitor is charged by a 10.0-V battery through a resistance R. The capacitor reaches a potential difference of 4.00 V at the instant 3.00 seconds after charging begins
1.) Find R
2.) Find the current at t=3.00 seconds after charging begins.

Homework Equations

i=$\frac{dq}{dt}$=-$\frac{CV_{ab}}{RC}$e$^{-t/RC}$

The Attempt at a Solution

so obviously I know how to find current but I need to find resistance and I cannot use R=V/I because it is non-ohmic! what do I do?

Find the time constant ##\tau = RC##. You know C...

why am i using time constant?

Eagle's Wings said:
why am i using time constant?

Read the question carefully. Some information you're given involves time. If you can find the time constant RC and you already know C then...

I would suggest using the equation i=\frac{dq}{dt}=-\frac{CV_{ab}}{RC}e^{-t/RC} to solve for R instead of using the traditional Ohm's law equation R=V/I. This is because the circuit in question is non-ohmic, meaning that the resistance is not constant and varies with the voltage and current. By using the non-ohmic equation, we can accurately calculate the resistance at any given time, including t=3.00 seconds.

1. What is resistance and current non-ohmic?

Resistance is a measure of how difficult it is for electrons to flow through a material. Current non-ohmic refers to a situation where the current does not vary linearly with the voltage, as predicted by Ohm's Law.

2. How do you calculate resistance?

Resistance is calculated by dividing the voltage by the current. This is represented by the formula R = V/I, where R is resistance, V is voltage, and I is current.

3. What are some examples of non-ohmic materials?

Some common examples of non-ohmic materials include diodes, transistors, and semiconductors. These materials have a non-linear relationship between voltage and current, making them non-ohmic.

4. How is resistance different from impedance?

Resistance is a measure of how a material resists the flow of electric current, while impedance is a measure of how a circuit responds to both current and voltage. Impedance includes both resistance and reactance, which is a measure of how a circuit responds to AC signals.

5. What are some factors that can affect resistance and current non-ohmic?

Some factors that can affect resistance and current non-ohmic include temperature, material composition, and the presence of impurities or defects in the material. Additionally, the shape and size of the material can also impact its resistance and non-ohmic behavior.

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