THE PRACTICE STUDIO
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PRACTICE / RC transients
Read capacitance from a logarithmic graph
During discharge, a graph of ln(V/V₀) vertically against t in seconds is a straight line through (0 s, 0) and (4 s, −2). The resistance is 2.0 kΩ.
| Time (s) | ln(V/V₀) |
|---|---|
| 0 | 0 |
| 4 | −2 |
Find the capacitance.
Organize the givens & assumptions
- R = 2.0 kΩ
- Vertical axis: ln(V/V₀)
- Time axis in seconds; line points listed in the table
Ideal single-capacitor discharge; V and V₀ have the same positive sign. The fitted line is exact for this question.
- A
- B
- C
- D
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