2016-E6A: Semiconductor materials and devices: semiconductor materials; germanium, silicon, P-type, N-type; transistor types: NPN, PNP, junction, field-effect transistors: enhancement mode; depletion mode; MOS; CMOS; N-channel; P-channel
In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?
In microwave circuits
In high-current rectifier circuits
In high-power audio circuits
In very low frequency RF circuits
Which of the following semiconductor materials contains excess free electrons?
Why does a PN-junction diode not conduct current when reverse biased?
Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
Only P-type semiconductor material can conduct current
Only N-type semiconductor material can conduct current
Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?
What is the alpha of a bipolar junction transistor?
The change of collector current with respect to emitter current
The change of collector current with respect to base current
The change of base current with respect to collector current
The change of collector current with respect to gate current
What is the beta of a bipolar junction transistor?
The change in collector current with respect to base current
The frequency at which the current gain is reduced to 1
The breakdown voltage of the base to collector junction
The switching speed of the transistor
Which of the following indicates that a silicon NPN junction transistor is biased on?
Base-to-emitter voltage of approximately 0.6 to 0.7 volts
Base-to-emitter resistance of approximately 6 to 7 ohms
Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
Base-to-emitter voltage of approximately 6 to 7 volts
What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?
Alpha cutoff frequency
Alpha rejection frequency
Beta cutoff frequency
What is a depletion-mode FET?
An FET that exhibits a current flow between source and drain when no gate voltage is applied
An FET that has no current flow between source and drain when no gate voltage is applied
Any FET without a channel
Any FET for which holes are the majority carriers
In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?
In Figure E6-2, what is the schematic symbol for a P-channel junction FET?
Why do many MOSFET devices have internally connected Zener diodes on the gates?
To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
To provide a voltage reference for the correct amount of reverse-bias gate voltage
To protect the substrate from excessive voltages
To keep the gate voltage within specifications and prevent the device from overheating
What do the initials CMOS stand for?
Complementary Metal-Oxide Semiconductor
Common Mode Oscillating System
Complementary Mica-Oxide Silicon
Common Mode Organic Silicon
How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?
An FET has high input impedance; a bipolar transistor has low input impedance
They are both low impedance
An FET has low input impedance; a bipolar transistor has high input impedance
They are both high impedance
Which semiconductor material contains excess holes in the outer shell of electrons?
What are the majority charge carriers in N-type semiconductor material?
What are the names of the three terminals of a field-effect transistor?
Gate, drain, source
Gate 1, gate 2, drain
Emitter, base, collector
Emitter, base 1, base 2
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