Electronic Devices - Operational Amplifiers - Discussion

Discussion Forum : Operational Amplifiers - General Questions (Q.No. 2)
2.

Refer to this figure. If the value of R1 decreases, the voltage gain will ________ and the input impedance will ________.

increase, increase
increase, decrease
decrease, decrease
decrease, increase
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
12 comments Page 1 of 2.

Assimo said:   2 years ago
@Khizer.

If the impedance decreases, then it increases but in negative.

Ooredoo said:   4 years ago
Explain about input impedance, please.

Abdul Qayum said:   5 years ago
Thanks @Arvind.

Lakshmi said:   10 years ago
@Subbu.

How do say R1 is input resistance?

Aravind said:   1 decade ago
@Khizer:

Actually the negative sign indicates that the output will be shifted by 180 degree. So no need to consider about that negative sign.

Khizer said:   1 decade ago
Here answer is wrong. Because of minus sign. If R1 decreases then the answer will be big but in negative.

Subbu said:   1 decade ago
R1 only input impedance.

If R1 decreases then automatically input impedance decrease.

Rishikesh said:   1 decade ago
What about Impedance?

Srinivas said:   1 decade ago
It is invert op-amp so gain= -Rf/R1.

Ami said:   1 decade ago
Gain is indirectly/inversly proportional to rf/r1 as gain increse result decrease.


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