Question

A practical op-amp has a bandwidth of only 10 Hz. Gain is 10^6, and the required bandwidth is 100 kHz. How much feedback is required?

(a) 0.99% negative feedback

(b) 0.99% positive feedback

(c) 1% negative feedback

(d) 1% positive feedback

This question was posed to me in examination.

My question is based upon Operational Amplifiers in section Op-amps and its Applications of Analog Circuits

Answer 1

Right option is (a) 0.99% negative feedback

For explanation I would say: B2 = B1(1+βA) = 10(1+β10^6) = 100k

1 + β10^6 = 10k

β = 9.999×10^-3

In percentage, feedback β = 0.99% negative feedback.