Concepts Of Physics MCQ Edition [Volume 2]PhysicsSemiconductors and Semiconductor Devices
An amplifier circuit employs a transistor in common-emitter mode, with a load resistor of 2 k connected in the collector branch. The transistor has a current gain = 50 and an input resistance of 0.50 k . When the input current is altered by 50 A , determine the change in the input voltage.
Options
- A10 mV
- B50 mV
- C25 mV
- D2.5 mV
Correct answer
C. 25 mV
Step-by-step solution
Given: Input resistance, R_ in = 0.50 k = 500 Change in input current, I_B = 50 A = 50 10⁻⁶ A The change in input voltage is given by Ohm's law applied to the input circuit: V_ in = I_B R_ in V_ in = (50 10⁻⁶ A ) (500 ) V_ in = 25000 10⁻⁶ V V_ in = 25 10⁻³ V = 25 mV