Question T6B10
From subelement T6 - T6B
Which of the following can provide power gain?
Why is this correct?
A transistor can provide power gain by amplifying signals—taking a small input signal and producing a larger output signal. This amplification ability is fundamental to transistors' operation as active components. Transformers (A) can change voltage levels but cannot provide power gain since they're passive devices bound by conservation of energy. Reactors (C) are inductors that store energy but don't amplify. Resistors (D) only dissipate energy as heat and cannot amplify signals.
Memory tip
Look for the key word 'power' in gain questions—only active components like transistors can actually increase signal power by using an external power source. Passive components can only redistribute or reduce power, never increase it.
Learn more
Why do you think a transistor needs three terminals (emitter, base, collector for BJT or gate, drain, source for FET) while components that can't provide gain typically have only two?
Think about it
Active components need external power sources to function, while passive components work with energy already in the circuit. Transistors use a control signal to regulate current flow from a power supply, allowing a small input to control a much larger output current. This controlled amplification is what enables everything from audio amplifiers in transceivers to RF power amplifiers that boost your signal for transmission across greater distances.