Which of the following is NOT true for a common collector transistor?

Question

Question

This question was previously asked in

PGCIL DT Electrical 12 March 2022 (NR II) Official Paper

Answer 1

The correct answer is option 4):(Power gain is high)

Concept:

The input impedance is high in the common collector because this is calculated by the Beta (gain) of the transistor, multiplied by the emitter resistance, whereas the current gain is due to the output impedance being inversely proportional to the current gain of the transistor in parallel to R_e
Common collector configuration, also known as emitter follower provides high input impedance and low output impedance. So they are used for the purpose of impedance matching.
In common collector configuration, the collector terminal is common to both input and output terminals. The current gain in the common-collector configuration is therefore the ratio of the emitter current to the base current. Since the emitter current is very high as compared to the base current, we get current amplification. It provides a voltage gain of less than unity.
common collector configuration has low voltage gain and high current gain. The power gain of the common collector amplifier is medium. so option 4 is wrong