Advanced Qualification · A-002 Advanced components and circuits · A-002-007-005
In the common base amplifier, the input impedance, when compared to the output impedance is:
- A only slightly lower
- B very high
- C very low
- D only slightly higher
Correct answer: C — very low. From the official ISED question bank, verified word for word.
Why
In a common base amplifier, the signal enters at the emitter, which presents a very easy path for current to flow, resulting in an input impedance that is very low compared to the high impedance found at the collector output. The full explanation — and one for every question — is in Pro.
Practise this section
Advanced components and circuits: semiconductors, amplifier classes, oscillators, mixers, filters and digital logic.