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NEET PHYSICSSEMICONDUCTOR ELECTRONICSMedium

Question

In a common-emitter transistor amplifier, the audio signal voltage across the collector is 3 V3\text{ V}. The resistance of the collector is 3 kΩ3\text{ k}\Omega. If the current gain is 100100 and the base resistance is 2 kΩ2\text{ k}\Omega, the voltage and power gain of the amplifier are:

A

100 and 1000

B

15 and 200

C

150 and 15000

D

20 and 2000

Step-by-Step Solution

  1. Identify the Given Data: Collector resistance (output resistance), Rc=3 kΩR_c = 3\text{ k}\Omega Base resistance (input resistance), Rb=2 kΩR_b = 2\text{ k}\Omega Current gain, β=100\beta = 100 (Note: The 3 V3\text{ V} collector voltage is extra information not needed for finding the gains if β\beta and the resistances are known).
  2. Calculate Voltage Gain (AvA_v): The voltage gain in a common-emitter amplifier is the product of current gain and resistance gain. Av=β×RcRbA_v = \beta \times \frac{R_c}{R_b} Av=100×3 kΩ2 kΩ=100×1.5=150A_v = 100 \times \frac{3\text{ k}\Omega}{2\text{ k}\Omega} = 100 \times 1.5 = 150
  3. Calculate Power Gain (ApA_p): The power gain is the product of current gain and voltage gain. Ap=β×AvA_p = \beta \times A_v Ap=100×150=15000A_p = 100 \times 150 = 15000
  4. Conclusion: The voltage gain is 150150 and the power gain is 1500015000.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from SEMICONDUCTOR ELECTRONICS. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSSEMICONDUCTOR ELECTRONICScommonemittertransistoramplifiersignalvoltage

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