JFET is a/an ________ device.
unipolar
Understanding JFETs: Unipolar or Bipolar Device?
The question asks to identify the classification of a JFET as a type of semiconductor device. Semiconductor devices can be broadly classified based on how the current conduction takes place within them.
There are two main categories regarding current conduction:
- Bipolar Devices: In these devices, current is carried by two types of charge carriers: both electrons (negative carriers) and holes (positive carriers). The operation relies on the interaction between these two types of carriers. A common example of a bipolar device is the Bipolar Junction Transistor (BJT).
- Unipolar Devices: In contrast, unipolar devices conduct current using primarily only one type of charge carrier. This carrier can be either electrons or holes, depending on the specific construction of the device (N-channel or P-channel). The operation is controlled by an electric field, which modulates the conductivity of the channel through which the majority carriers flow.
A JFET, which stands for Junction Field-Effect Transistor, is a type of transistor that falls into the unipolar category. In a JFET, the current flow between the source and drain terminals is controlled by the voltage applied to the gate terminal. This gate voltage creates an electric field that modulates the width of the channel and thus controls the flow of majority carriers (either electrons in an N-channel JFET or holes in a P-channel JFET).
Because the current conduction in a JFET relies predominantly on only one type of charge carrier (either electrons or holes), it is classified as a unipolar device.
Therefore, a JFET is a unipolar device.
Important Questions from Types of FET
The transconductance g mof a JFET is equal to:
\(\frac{ I _{ DSS }}{ V _{ P }}\left(1-\frac{ V _{ GS }}{ V _{ P }}\right)\)
The CMOS inverter can be used as an amplifier when:
In JFET, the Pinch‐off Voltage can be defined as:
In JFET, the current density in the x-direction is:
A. σ(x)E x
B. qN DμE x
C. \(\rm \frac{q}{2 \in_s}N_D\mu\)
D. \(\rm \frac{N_D\mu}{2 \in_s}\)
Choose the correct answer from the options given below:
Match List I with List II
List – I
List – II
JFET - Bias
Characteristic Equation
A.
Self - bias
I.
\(\rm I_D = \frac{V_{SS}-V_{GS}}{R_S}\)
B.
Voltage – divider bias
II.
\(\rm I_D = \frac{V_{EE}-V_{BE}}{R_E}\)
C.
Source bias
III.
V GS = -I DR S
D.
Current – source bias
IV.
\(\rm I_D = \frac{V_{G}-V_{GS}}{R_S}\)
Choose the correct answer from the options given below:
