Advertisements
Advertisements
प्रश्न
Define the terms : Input resistance How are these determined using typical input and output characteristics?
Advertisements
उत्तर
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
संबंधित प्रश्न
Draw a circuit diagram of a p-n-p transistor and explain how it works as a transistor amplifier
Draw a circuit diagram of a transistor amplifier in CE configuration.
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
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 labelled diagram of a common emitter amplifier, showing waveforms of the signal voltage and output voltage.
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?
Draw a circuit diagram for the common emitter transistor amplifier. What is meant by phase reversal?
In a CE transistor amplifier, the audio signal voltage across the collector resistance of2 kΩ is 2 V If the base resistance is 1 kΩ and the current amplification of the transistor is 100, the input signal voltage is
A pnp transistor is used in common-emitter mode in an amplifier circuit. A change of 40 µA in the base current brings a change of 2 mA in collector current and 0.04 V in base emitter voltage. Which of the following is the correct value of the input resistor Rin?
