EASY
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How do you find the operating point of a transistor?

Important Questions on Semiconductor Devices

MEDIUM

The transfer characteristic curve of a transistor, having input and output resistance 100 Ω and 100 kΩ respectively, is shown in the figure. The voltage and power gain, are respectively:
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MEDIUM
Draw the circuit arrangement for studying the output characteristics of n-p-n transistor in CE configuration. Explain how the output characteristics is obtained.
MEDIUM
An NPN transistor is used in common emitter configuration as an amplifier with 1 kΩ load resistance. Signal voltage of 10 mV is applied across the base-emitter. This produces a 3 mA change in the collector current and 15 μA  change in the base current of the amplifier. The input resistance and voltage gain are:
MEDIUM

In the following common emitter circuit, β=100 and VCE=7 V. If VBE is negligible, then the base current is

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EASY
For a common emitter configuration, if α and β have their usual meanings, the correct relationship between α and β is:
EASY
For transistor action, which of the following statements is correct?
MEDIUM
A common emitter amplifier circuit, built using an NPN transistor, is shown in the figure. Its dc current gain is 250RC=1  and VCC=10 V . The minimum base current for VCE to reach saturation is

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EASY
Let ie, ic and ib represent emitter current, collector current and the base current of a transistor, then
EASY
An unknown transistor needs to be identified as a npn or pnp type. A multimeter, with +ve and -ve terminals, is used to measure resistance between different terminals of transistor. If terminal 2 is the base of the transistor then which of the following is correct for a pnp transistor?
HARD
A realistic graph depicting the variation of the reciprocal of input resistance in an input characteristics measurement in a common emitter transistor configuration is :
HARD

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In the circuit shown, the value of β of the transistor is 48. If the supplied base current is 200 μA, what is the voltage at the terminal Y?

MEDIUM

In the figure, given that VBB supply can vary from 0 to 5.0 V, VCC=5 V, βdc=200, RB=100 , RC=1  and VBE=1.0 V. The minimum base current and the input voltage at which the transistor will go to saturation, will be, respectively:

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EASY
In a transistor circuit, the collector current is changed by 89 mA, if the emitter current is changed to 9.0 mA. The value of current amplification factor, β is
MEDIUM

The output characteristics of a transistor is shown in the figure. When VCE is 10V and IC=4.0mA, then value of βac is 

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EASY
For a CE transistor amplifier the audio signal voltage across the collector resistance of 2kΩ is 2 V. The current amplification factor of the transistor is 100 . If the base resistance is 1kΩ, the input signal voltage and base current are respectively
EASY
In a common base circuit, collector base voltage changes by 0.6 V and collector current changes by 0.02 mA. Then, the output resistance is
HARD
The dc common-emitter current gain of a N-P-N transistor is 50 . The potential difference applied across the collector and emitter of a transistor used in CE configuration is, VCE=2V. If the collector resistance, RC=4 KΩ, the base current IB and the collector current IC will be:
EASY
The ratio (R) of output resistance r0, and the input resistance ri in measurements of input and output characteristics of a transistor is typically in the range :
MEDIUM

An n-p-n transistor has three leads A, B and C. Connecting B and C by moist fingers, A to the positive lead of an ammeter, and C to the negative lead of the ammeter, one finds large deflection. Then, A, B and C refer respectively to :

HARD
Draw a neat circuit diagram to study the input and output characteristics of a common emitter transistor.