Question

The voltage gain and current gain of a transistor amplifier in common emitter configuration are respectively 150 and 50. If the resistance in the base circuit is 850 \(\Omega\), then the resistance in the collector circuit is:

• A. \( 1700 \, \Omega \)
• B. \( 2250 \, \Omega \)
• C. \( 2550 \, \Omega \)
• D. \( 3000 \, \Omega \)

Hint:

In transistor circuits, understanding the relationship between current and voltage gains and how they relate to resistances in different parts of the circuit (like base and collector) is crucial for correctly analyzing the circuit’s behavior.

Answer 1

The Correct Option is C

Step 1: The resistance in the collector circuit \( R_C \) can be estimated using the voltage gain \( A_V \), current gain \( A_I \), and the resistance in the base circuit \( R_B \). Given: \[ A_V = 150, \quad A_I = 50, \quad R_B = 850 \, \Omega \] Step 2: The relationship involving these parameters to find \( R_C \) typically involves the use of formulas relating voltage and current gains with resistances in different parts of the circuit. The following formula can be applied in some cases for common emitter amplifiers: \[ R_C = A_V \times R_B / A_I \] Substituting the given values: \[ R_C = \frac{150 \times 850}{50} = 2550 \, \Omega \]