Amateur ExtraE7G08
How does the gain of an ideal operational amplifier vary with frequency?
D
Answer
Practical circuits and system design
Type
A
It increases linearly with increasing frequency
B
It decreases linearly with increasing frequency
C
It decreases logarithmically with increasing frequency
D
It does not vary with frequency
Answer Notes
When dealing with theoretical or 'ideal' electronic components, we assume perfect characteristics that do not actually exist in the real world. For an ideal operational amplifier, the open-loop gain is assumed to be infinite, and its bandwidth is also assumed to be infinite.
Because the theoretical bandwidth is infinite, the gain does not decrease or vary as the frequency changes. It remains constant regardless of how high the frequency goes.
In contrast, a real-world op-amp has a finite gain-bandwidth product, meaning its gain drops as frequency increases. Questions specifying an 'ideal' op-amp are specifically testing your knowledge of theoretical models versus practical limitations.
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What voltage gain can be expected from the circuit in Figure E7-3 when R1 is 10 ohms and RF is 470 ohms?
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What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1,000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?