In a BJT circuit a pnp transistor is replaced by npn transistor. To an...
Explanation:
When a pnp transistor is replaced by an npn transistor in a BJT circuit, the polarity of voltages and currents will be reversed. Therefore, to analyze the new circuit, all calculated voltages and currents must be replaced by reverse values.
Details:
- BJT Circuit: A bipolar junction transistor (BJT) is a three-layer semiconductor device consisting of a p-type or n-type semiconductor sandwiched between two n-type or p-type semiconductors. It can be used as a switch or amplifier in electronic circuits.
- PNP Transistor: A pnp transistor consists of a p-type emitter, an n-type base, and a p-type collector. It is biased in such a way that the base-emitter junction is forward-biased, while the collector-base junction is reverse-biased.
- NPN Transistor: An npn transistor consists of an n-type emitter, a p-type base, and an n-type collector. It is biased in such a way that the base-emitter junction is forward-biased, while the collector-base junction is reverse-biased.
- Replacing PNP with NPN: When a pnp transistor is replaced by an npn transistor, the polarities of voltages and currents in the circuit will be reversed. For example, the direction of the base current and collector current will be reversed, and the voltage drops across the base-emitter and collector-emitter junctions will be reversed.
- Analyzing the New Circuit: To analyze the new circuit, all calculated voltages and currents from the previous analysis must be replaced by reverse values, taking into account the new polarities. This means that the signs of all voltages and currents must be changed, and the magnitudes may also change depending on the specifics of the circuit.
- Option D is Correct: Therefore, the correct answer is option D, which states that all calculated voltages and currents must be replaced by reverse values. Options A, B, and C are incorrect because they only partially address the issue of polarity reversal and may lead to incorrect analysis of the circuit.
In a BJT circuit a pnp transistor is replaced by npn transistor. To an...
All voltages and currents have reverse polarity.