An amplifier without feedback has a voltage gain of 50, input resistance of 1 kΩ and output resistance of 2.5 kΩ. The input resistance of the current shunt -ve feedback amplifier using the above amplifier with a feedback factor of 0.2 is

• 1/11 kΩ
• 1/5 kΩ
• 5 kW
• 11 kW

Correct Answer: 1/11 kΩ

Explanation:

Input Resistance with feedback for current shunt, .