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The phase shift oscillator shown below operate at f = 80 kHz. The value of resistance RF is:
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- 148 kΩ
- 236 kΩ
- 438 kΩ
- 814 kΩ
Correct Option: B
Frequency of oscillation in the phase shift oscillator,
| f = | ||
| 2π 6 RC |
| 80 × 103 = | ||
| 2π 6 × R × 100 × 10–12 |
| or R = | ||
| 8 × 2π × 6 |
or R = 8.12 kΩ
| and, gain = | = 29 | |
| R |
or RF = 29 R = 29 × 8.12 kΩ = 235.65 kΩ
or RF 236 kΩ