For a common emitter transistor amplifier, the output voltage across the collector resistance of 2 kΩ is 2 V . If the current amplification factor β = 100 . Find the input signal voltage. The base resistance is 1 kΩ .

The output voltage V o = 2 V . The collector resistance R C = 2000 V . The current amplification factor β = 100 . The base resistance R B = 1000 V . As we know that the voltage gain A v = V o V i = β R o R i = β R L R B . The input voltage V i = V o R L βR C , Substituting the given values, we get, V i = 2 × 1000 100 × 2000 = 0 . 01 V . Hence, the input voltage is 0 . 01 V .

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If the base and collector of a transistor are in forward biased, it is not used as a :-

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Important Questions on Semiconductor Devices and their Applications

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure.

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The estimated current gain from the figure is

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

If the base and collector of a transistor is in forward bias, then it can not be used as

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

Two amplifiers are connected one after the other in series (cascaded). The first amplifier has a voltage gain of

10

and the second has a voltage gain of

20 .

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0.01

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

The emitter junction of the CE transistor amplifier is ______ biased while the collector junction is _____ biased.

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

For a transistor amplifier, the voltage gain

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

In a common emitter transistor amplifier,

β = 60

R_{0} = 5000 Ω

and internal resistance of a transistor is

500 Ω

. The voltage amplification of the amplifier will be

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

A transistor works as an amplifier when,

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

Draw a labelled diagram of a common emitter amplifier, showing waveforms of signal voltage and output voltage.

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

A common emitter transistor amplifier is connected with a load resistance of

6 kΩ

. When a small

A C

signal of

15 mV

is added to the base-emitter voltage, the alternating base current is

20 μ A

and the alternating collector current is

1.8 mA

. What is the voltage gain of the amplifier?

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

For a CE transistor amplifier the audio signal voltage across the collector resistance of

2 k Ω

2 V

. The current amplification factor of the transistor is

100 .

If the base resistance is

1 k Ω

, the input signal voltage and base current are respectively

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

If $α = 0.99$ for a CE transistor amplifier circuit. The input resistance is equal to $1 kΩ$ and the load resistance is equal to $100 kΩ$ to , the voltage gain of the circuit is

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

In a common base mode of a transistor, the collector current is

5.488 mA

for an emitter current of

5.60 mA

. The value of the base current amplification factor

(β)

will be

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

A transistor is preferred to a triode valve in amplifier circuit because it

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

For a common emitter transistor amplifier, the output voltage across the collector resistance of

2 kΩ

2 V

. If the current amplification factor

β = 100

. Find the input signal voltage. The base resistance is

1 kΩ

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

Draw circuit diagram for a

NPN -

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

Draw a labelled circuit diagram of a transistor acting as a common emitter amplifier. What is meant by phase reversal?

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

In a

C E

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

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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 $Y$ ?

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Physics>Modern Physics>Semiconductor Devices and their Applications>Transistor as an Amplifier

In a common emitter amplifier, the input resistance and output resistance are $200 Ω$ and $500 Ω$ respectively. If the voltage gain of the amplifier is $50$ , then the power gain is

If the base and collector of a transistor are in forward biased, it is not used as a :-

Important Questions on Semiconductor Devices and their Applications

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