Electronic Devices 9th Edition Chapter 8: Field Effect Transistors

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What is the primary function of a reverse-biased pn junction in a JFET?

To amplify the input signal

To reduce the input impedance

To increase the output voltage

To control current in a channel (correct)

What is the difference between an n-channel and a p-channel JFET?

The direction of current flow

The structure of the device (correct)

The number of terminals

The type of material used in the construction

What are the three terminals of an n-channel JFET?

Collector, base, and emitter

Drain, gate, and collector

Drain, base, and emitter

Drain, gate, and source (correct)

What is the purpose of the p-type regions in an n-channel JFET?

To form a channel Signup and view all the answers

What is the function of the gate lead in a JFET?

To connect the two p-type regions Signup and view all the answers

What is the difference between a JFET and a BJT?

The operating principle Signup and view all the answers

What is IDSS in the context of JFETs?

The maximum drain current that a JFET can produce regardless of the external circuit Signup and view all the answers

What happens to a JFET when it reaches breakdown?

It can result in irreversible damage to the device Signup and view all the answers

What is the effect of increasing the magnitude of VGS to larger negative values on the drain current?

It decreases the drain current Signup and view all the answers

What is the region of operation where the JFET produces a constant current?

Active region Signup and view all the answers

What is the purpose of applying a reverse-bias voltage, VGG, from gate to source?

To produce a family of drain characteristic curves Signup and view all the answers

What is the term for the point where the drain current becomes constant?

Pinch-off Signup and view all the answers

What is the primary purpose of determining ID in a JFET amplifier?

To calculate the Q-point of an amplifier Signup and view all the answers

What is the graphical approach used to find ID based on?

The transfer characteristic curve Signup and view all the answers

Why are capacitors removed from the circuit in the DC analysis?

Because they are open to DC Signup and view all the answers

What is the assumption made about the voltage source in the AC equivalent circuit?

It has a zero internal resistance Signup and view all the answers

What is the AC equivalent circuit based on?

The assumption that XC > 0 at the signal frequency Signup and view all the answers

What is the AC potential of the VDD terminal in the AC equivalent circuit?

A zero-volt potential Signup and view all the answers

What is the main purpose of RG in amplifier applications?

To isolate an ac signal from ground and force the gate to be at 0 V Signup and view all the answers

What is the relationship between IS and ID in a JFET?

IS is equal to ID Signup and view all the answers

What is the effect of the current through RS on the source of a p-channel JFET?

It produces a negative voltage at the source Signup and view all the answers

How is the drain voltage with respect to ground determined in a JFET?

By setting the Q-Point of the JFET Signup and view all the answers

What is the purpose of setting the Q-Point of a JFET?

To establish a JFET bias point Signup and view all the answers

What is the relationship between VG and VS in an n-channel JFET?

VG is 0, and VS is positive with respect to ground Signup and view all the answers

What is the characteristic of the input resistance to a JFET?

High Signup and view all the answers

What is the condition required for the expression of JFET voltage gain in Equation 9-1 to be applicable?

Source terminal at ac ground Signup and view all the answers

What is the primary contributor to the voltage at the gate in the circuit shown in Figure 9-8(b)?

Input voltage from the signal source Signup and view all the answers

What is the purpose of the ac voltage source in the circuit shown in Figure 9-8(b)?

To provide an ac signal to the input Signup and view all the answers

What is the configuration of the amplifier being discussed in the context of Equation 9-1?

Common-source amplifier Signup and view all the answers