-
For a high pass RC circuit, when subjected to a unit step input voltage the voltage across the capacitor will be—
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- 1 – e– t/RC
- e– t/RC
- e + t/RC
- 1
Correct Option: A
Voltage across capacitor
| = | |||
| V0(s) | |||
| Vi(s) | |||
| Cs |
where Vi (t) = u(t)
| Vi (s) = | s |
| V0(s)=Vi (s) | RCs + 1 |
| V0(s) = | · |  |  | ||
| s | RCs + 1 |
By using partial fraction
| V0(s) = | + | |||
| s | RCs + 1 |
| V0(s) = | + | |||
| s | RCs + 1 |
| V0(s) = | – | RC | |||||
| s | RC | | s + | | |||
| RC | |||||||
Taking inverse Laplace transform
V0(t) = 1 – e– t/RC
Hence alternative (A) is the correct choice.
