6. Negative feedback in an amplifier :
(a) lowers its lower 3 dB frequency
(b) raises its upper 3 dB frequency
(c) increases its bandwidth
(d) all of the above
7. Regarding negative feedback in amplifiers which statement is WRONG ?
(a) it widens the separation between 3 dB frequencies
(b) it increases the gain-bandwidth product
(c) it improves gain stability
(d) it reduces distortion
8. Negative feedback reduces distortion in an amplifier only when it :
(a) comes as part of input signal
(b) is part of its output
(c) is generated within the amplifier
(d) exceeds a certain safe level
9. The shunt-derived series-fed feedback in an amplifier :
(a) increases its output impedance
(b) decreases its output impedance
(c) increases its input impedance
(d) both (b) and (c)
10. The gain of a negative feedback amplifier is 40 dB. If the attenuation of the feedback path is 50 dB, then the gain of the amplifier without feedback is :
(a) 78.92
(b) 146.32
(c) 215.51
(d) 317.23
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- Amplifiers » Exercise - 131. When current feedback (negative) is applied to an amplifier, its output impedance ...... (a) is increased (b) is decreased (c) remains the same (d) none of the above
- Feedback Amplifiers » Exercise - 12. Feedback in an amplifier always helps to : (a) control its output (b) increase its gain (c) decrease its input impedance (d) stabilize its gain
- Feedback Amplifiers » Exercise - 14. Closed-loop gain of a feedback amplifier is the gain obtained when : (a) its output terminals are closed (b) negative feedback is applied (c) feedback loop is closed (d) feedback factor exceeds unity