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**Home ⇒ Overview Courses ⇒ Electrical engineering ⇒ Capacitor to DC voltage ⇒ Exercises**

### Exercises - Capacitor

#### Part 1: Checkbox tasks - Capacitors

- only one is right at a time!

#### Part 2: Capacitor connected to DC voltage

A capacitor with a capacitance of C = 4.7 µF is charged via a resistor of 1 kΩ. The following diagram shows the capacitor voltage as a function of time t.

Determine the time constant of this resistor-capacitor series

Determine the instantaneous current at time t = 0 s

Determine the instantaneous current at time t = 5 ms

You can determine the time constant τ:

Either via τ = R · C = 1 kΩ · 4.7 µF = 4,7 ms

or graphically:

At time t = 0 s, the charging current is only limited by the ohmic resistance R of 1 kΩ:

I ( t = 0 ms) = U / R = 100 V / 1 kΩ = 0,1 A

At time t = 5 ms you get for V_{C} ≈ 73 V, therefore V_{R} ≈ 27 V

=> I (5 ms) = 27 V / 1 kΩ = 0,27 A