Advertisements
Advertisements
Question
Define the terms : Input resistance How are these determined using typical input and output characteristics?
Solution
Input resistance may be defined as the ratio of small change in the base-emitter voltage (ΔVBE) to the resulting change in base current (IB) at constant collector-emitter voltage (VCE).
Input resistance, `R_i=(DeltaV_(BE))/(DeltaI_B)`
To find the input resistance, mark a point P on the input characteristic. Now, draw a tangent at point P. The reciprocal of slope of AB will give the input resistance
APPEARS IN
RELATED QUESTIONS
For a CE-transistor amplifier, the audio signal voltage across the collector resistance of 2 kΩ is 2 V. Suppose the current amplification factor of the transistor is 100, find the input signal voltage and base current if the base resistance is 1 kΩ.
With the help of necessary circuit diagram, describe briefly how n-p-n transistor in CE configuration amplifies a small sinusoidal input voltage. Write the expression for the ac current gain
Under what condition does the transistor act as an amplifier?
Derive an expression for voltage gain of the amplifier and hence show that the output voltage is in opposite phase with the input voltage.
Draw a circuit diagram for studying the input and output characteristics of a n-p-n transistor in common emitter configuration. Using the circuit, explain how input, output characteristics are obtained
Gautam went for a vacation to the village where his grandmother lived. His grandmother took him to watch 'nautanki' one evening. They noticed a blackbox connected to the mike lying nearby. Gautam's grandmother did not know what that box was. When she asked this question to Gautam, he explained to her that it was an amplifier.
(i) Which values were displayed by the grandmother? How can inculcation of these values in students be promoted?
(ii) What is the function of an amplifier?
(iii) Which basic electronic device is used in the amplifier?
Consider an amplifier circuit using a transistor. The output power is several times greater than the input power. Where does the extra power come from?
Write the truth table of the following circuit. Name the gate represented by this circuit.
In a common base amplifier, the phase difference between the input signal voltage and output voltage is ______.
When a junction transistor is used as an amplifier in CE-mode,
