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Amplifiers and Operational Amplifiers

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do feedback resistors set the gain of an op-amp amplifier, and how do the inverting and non-inverting configurations differ?

Apply the gain equations for the inverting and non-inverting op-amp amplifier and explain the role of negative feedback
A focused answer to the O-Level Electronics outcome on op-amp amplifiers. The inverting and non-inverting gain equations, the role of negative feedback, and choosing resistors for a wanted gain.
9 min answer →

How does an operational amplifier compare two voltages and give a clear high or low output that can switch a circuit?

Explain the operational amplifier used as a comparator, including its very high gain and the two output states
A focused answer to the O-Level Electronics outcome on the op-amp comparator. The two inputs, very high open-loop gain, the high or low output, and using a sensor divider with a reference voltage.
8 min answer →

How can a single transistor amplify a small signal, and why must it be biased before it can do so?

Explain how a single transistor amplifies a small signal, the need for biasing, and the meaning of voltage amplification
A focused answer to the O-Level Electronics outcome on the transistor amplifier. How a small base signal controls a large collector current, the need for biasing, and voltage amplification.
8 min answer →

What does it mean for an amplifier to have gain, and how is that gain expressed as a ratio and in decibels?

Define voltage gain as a ratio, calculate it, and express it in decibels using the gain equation
A focused answer to the O-Level Electronics outcome on amplifier gain. Voltage gain as the ratio of output to input, calculating it, and expressing gain in decibels.
8 min answer →