In the circuit shown in Figure 18-33,the JFET functions as a
A) voltage-controlled resistance.
B) power amplifier.
C) voltage regulator.
D) preamp.

Question

In the circuit shown in Figure 18-33,the JFET functions as a 
A) voltage-controlled resistance. 
B) power amplifier. 
C) voltage regulator. 
D) preamp.

Quizplus · Accepted Answer

In a JFET, the channel resistance can be controlled by the voltage applied to the gate. Therefore, it functions as a voltage-controlled resistor, which is used in the circuit as shown in Figure 18-33. The JFET is used as a variable resistor to control the gain of the operational amplifier, which functions as an inverting amplifier. Hence, the best choice is option A.

In the Circuit Shown in Figure 18-33,the JFET Functions as a