12. Field-effect transistor uses ________ to control the shape.
A. electric field
B. magnetic field
C. current distribution
D. voltage distribution
Answer: A
Field-effect transistor uses an electric field to control the shape and hence the electrical conductivity of the channel.
13. Field effect transistors are known as
A. unipolar device
B. bipolar device
C. tripolar device
D. multipolar device
Answer: A
Field-effect transistors are unipolar transistors as they involve single-carrier-type operations.
14. The FET has __________ input impedance.
A. low
B. high
C. all of the mentioned
D. none of the mentioned
Answer: B
Field-effect transistors have high input impedance. The conductivity of non-FET transistors is regulated by the input current thus it has low input impedance.
15. Field-effect transistor’s conductivity is regulated by
A. input current
B. output current
C. terminal voltage
D. supply voltage
Answer: C
Field-effect transistor’s conductivity is regulated by the voltage applied to a terminal (the gate) which is insulated from the device.
16. In FET, the current enters the channel through
A. source
B. drain
C. gate
D. nodes
Answer: A
In a field-effect transistor, the current enters the channel through the source and the current leaves the junction through the drain.
17. Which terminal bias the transistor to operation?
A. source
B. drain
C. gate
D. base
Answer: D
Other than the three terminals, source-drain, and gate, there is a fourth terminal called a body or base. This is used to bias the transistor to operation.
18. In FET, the width is greater than the length of the gate.
A. true
B. false
Answer: A
In FET, the width is greater than the length of the gate. Length gives the distance between source and drain. Width is the extension of the transistor, in the direction perpendicular to the cross-section.
19. Which terminal controls the electron flow passage?
A. source
B. drain
C. gate
D. base
Answer: C
Gate permits the electron to flow through or block their passage by creating or eliminating the channel between source and drain.
20. The expansion of the depletion region in the n-channel device makes the channel
A. narrow
B. wide
C. does not affect the channel
D. cannot be determined
Answer: A
In the n-channel depletion mode device, as the depletion region width expands, it encroaches the channel from the sides and the channel becomes narrow.
