Biasing Modes MCQ Quiz - Objective Question with Answer for Biasing Modes - Download Free PDF

A correct answer is an option (1)

Instruction code

Concept:-

A group of bits that tells the computer to perform a specific operation is known as instruction code.

Key Points

• The instruction code is a set of bits that tells a computer how to do things like add, shift, subtract, complement, and so on.
• Memory-reference instruction, Register-reference instruction, and input-output instruction are the three types of instructions in a simple computer.
• Computer instruction is a binary code that controls how a computer performs micro-operations in a series.
• The design of bits in an instruction is supported by the instruction format. It has fields like opcode, operands, and addressing mode in it.

Additional InformationMicro-operation:- Micro-operations are operations performed on data stored in registers. A micro-operation is a simple operation that is carried out on data contained in one or more registers.

Accumulator:- In a computer's CPU, an accumulator is a register for short-term, intermediate storage of arithmetic and logic data.

Register:- A register is highly rapid computer memory that stores data/instructions in execution and is made up of a set of flip-flops and gates. A register is a device that can store one bit of data.

Concept:

There are different types of biasing circuits of BJT.

1. Fixed bias/ Base Bias

2. Biasing with Emitter resistance

3. Voltage divider bias

Fixed bias / Base bias 

b

Biasing with the emitter resistor

This emitter resistor provides the Negative feedback and thermal stability. In the CE amplifier configuration Emitter resistor is considered as feedback resistor which reduces the gain.

Voltage divider Bias

In all the stabilization circuits the output is taken at the collector so the resistor connected at that terminal is called as "Load resistor".

Conclusion:

Option 4 is correct.

Concept:

The modes of operation of an NPN BJT are as follow:

Application:

Given V_BE = 0.7 V which indicates a forward-biased Emitter-Base junction, and

V_CB = 0.2 V which indicates a Reverse biased Collector-Base junction.

So, the mode of operation of the given transistor will be Normal active mode.

Transistor Biasing:

Transistor Biasing is the process of setting a transistors DC operating voltage or current conditions to the correct level so that any AC input signal can be amplified correctly by the transistor

The steady-state operation of a transistor depends a great deal on its base current, collector voltage, and collector current values and therefore, if the transistor is to operate correctly as a linear amplifier, it must be properly biased around its operating point.

Transistor biasing is provided by a biasing circuit and there are five types of biasing in transistor

1. Fixed Base Biasing a Transistor

2. Collector Feedback Biasing a Transistor

3. Dual Feedback Transistor Biasing

4. Transistor Biasing with Emitter Feedback

5. Voltage Divider Transistor Biasing

The modes of operation of an npn BJT are as follow:

Notes:

• Transistors biasing is done to keep stable DC operating conditions needed for its functioning as an amplifier.
• A properly biased transistor must have its Q-point (DC operating parameters like IC and VCE) at the center of saturation mode and cut-off mode i.e. active mode.
• In the active mode of transistor operation, the base-emitter junction is forward biased and the base-collector junction is reverse biased.​

Transistor Biasing:

Transistor Biasing is the process of setting a transistors DC operating voltage or current conditions to the correct level so that any AC input signal can be amplified correctly by the transistor

The steady-state operation of a transistor depends a great deal on its base current, collector voltage, and collector current values and therefore, if the transistor is to operate correctly as a linear amplifier, it must be properly biased around its operating point.

Transistor biasing is provided by a biasing circuit and there are five types of biasing in transistor

1. Fixed Base Biasing a Transistor

2. Collector Feedback Biasing a Transistor

3. Dual Feedback Transistor Biasing

4. Transistor Biasing with Emitter Feedback

5. Voltage Divider Transistor Biasing

When the emitter/base junction of the transistor becomes reverse biased the collector current stops because transistor operates in cut off region.

Tips & Tricks

The modes of operation of an npn BJT are as follow:

Notes:

• Transistors biasing is done to keep stable DC operating conditions needed for its functioning as an amplifier.
• A properly biased transistor must have its Q-point (DC operating parameters like IC and VCE) at the center of saturation mode and cut-off mode i.e. active mode.
• In the active mode of transistor operation, the base-emitter junction is forward biased and the base-collector junction is reverse biased.​

Concept:

The modes of operation of an NPN BJT are as follow:

Application:

Given V_BE = 0.7 V which indicates a forward-biased Emitter-Base junction, and

V_CB = 0.2 V which indicates a Reverse biased Collector-Base junction.

So, the mode of operation of the given transistor will be Normal active mode.

DC-equivalent of a transistor in Common-Emitter configuration is as shown:

Apply KVL in Loop-1, we get:

-VCC + IC RC + VCE = 0

     …(1)

This equation is called the DC-load line, and is graphically represented as:

Since the graph is an I_C – V_CE curve, the Y – intercept can be obtained by putting the X – coordinate term (i.e. V_CE) as 0.

Putting V_CE = 0 in Equation (1), the DC load line Equation becomes:

At this point the transistor operates in the saturation region.

Q-point is the operating point of the transistor. It is selected in the middle of the active region because:

• It gives or provides maximum possible amplification to input sinusoidal signal without any distortion in the positive or negative half cycle.
• If the input signal is large then distortion may occur so it is best suited for a small input without a distorted output.
• The stability of the operating points depends on the type of bias used and not on the Qpoint. Voltage divider bias has better stability than a simple fixed bias circuit.

A correct answer is an option (1)

Instruction code

Concept:-

A group of bits that tells the computer to perform a specific operation is known as instruction code.

Key Points

• The instruction code is a set of bits that tells a computer how to do things like add, shift, subtract, complement, and so on.
• Memory-reference instruction, Register-reference instruction, and input-output instruction are the three types of instructions in a simple computer.
• Computer instruction is a binary code that controls how a computer performs micro-operations in a series.
• The design of bits in an instruction is supported by the instruction format. It has fields like opcode, operands, and addressing mode in it.

Additional InformationMicro-operation:- Micro-operations are operations performed on data stored in registers. A micro-operation is a simple operation that is carried out on data contained in one or more registers.

Accumulator:- In a computer's CPU, an accumulator is a register for short-term, intermediate storage of arithmetic and logic data.

Register:- A register is highly rapid computer memory that stores data/instructions in execution and is made up of a set of flip-flops and gates. A register is a device that can store one bit of data.

Concept:

The modes of operation of an NPN BJT are as follow:

Application:

Given V_BE = 0.7 V which indicates a forward-biased Emitter-Base junction, and

V_CB = 0.2 V which indicates a Reverse biased Collector-Base junction.

So, the mode of operation of the given transistor will be Normal active mode.

Concept:

There are different types of biasing circuits of BJT.

1. Fixed bias/ Base Bias

2. Biasing with Emitter resistance

3. Voltage divider bias

Fixed bias / Base bias 

b

Biasing with the emitter resistor

This emitter resistor provides the Negative feedback and thermal stability. In the CE amplifier configuration Emitter resistor is considered as feedback resistor which reduces the gain.

Voltage divider Bias

In all the stabilization circuits the output is taken at the collector so the resistor connected at that terminal is called as "Load resistor".

Conclusion:

Option 4 is correct.

Concept:

Relation between collector current and base current is given by I_C = βI_B

Where,    also  

Application:

Assuming all other parameter is same for both of the BJT.

Now,

= 380 mV

The given transmitter is a PNP transistor (direction of the arrow pointing the base)

The voltage at the base, collector, and emitter terminal is:

V_B = 0 V

V_B = 0.7 V

V_C = -5 V

∴ V_EB = 0.7 V (Forward-biased)

V_CB = -5V (Reverse biased)

∴ The transistor is operating in the forward active mode.