Extra exam question E7B09
Subelement E7, PRACTICAL CIRCUITS· Group E7B
What is characteristic of an emitter follower (or common collector) amplifier?
- A.Low input impedance and phase inversion from input to output
- B.Differential inputs and single output
- C.Acts as an OR circuit if one input is grounded
- D.Input and output signals in-phase (correct answer)
WhyAn emitter follower, or common collector amplifier, has input and output signals in phase. An emitter follower, also called a common collector amplifier, has its input and output signals in phase with each other, since the output is taken from the emitter, which follows the base voltage directly (minus a small, constant base-emitter drop), answer D. It has high, not low, input impedance and doesn't invert phase, doesn't have differential inputs with a single output (that's an op-amp-like configuration), and doesn't function as an OR circuit.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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