E6A: Semiconductor materials and devices: semiconductor materials (germanium, silicon, P-type, N-type); transistor types: NPN, PNP, junction, power; field-effect transistors: enhancement mode; depletion mode; MOS; CMOS; N-channel; P-channel
E6A01:
In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?
At microwave frequencies
In high-current rectifier circuits
In high-power audio circuits
At very low frequency RF circuits
E6A02:
What type of semiconductor material contains more free electrons than pure germanium or silicon crystals?
N-type
P-type
Bipolar
Insulated gate
E6A03:
What are the majority charge carriers in P-type semiconductor material?
Holes
Free neutrons
Free protons
Free electrons
E6A04:
What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?
Acceptor impurity
Insulator impurity
N-type impurity
Donor impurity
E6A05:
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
E6A06:
What is meant by 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
E6A07:
In Figure E6-1, what is the schematic symbol for a PNP transistor?
1
2
4
5
E6A08:
What term indicates the frequency at which a transistor grounded base current gain has decreased to 0.7 of the gain obtainable at 1 kHz?
Alpha cutoff frequency
Corner frequency
Alpha rejection frequency
Beta cutoff frequency
E6A09:
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
An FET without a channel so no current flows with zero gate voltage
An FET without a channel so maximum gate current flows
E6A10:
In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?
4
2
5
6
E6A11:
In Figure E6-2, what is the schematic symbol for a P-channel junction FET?
1
2
3
6
E6A12:
Why do many MOSFET devices have built-in gate-protective Zener diodes?
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
E6A13:
What do the initials CMOS stand for?
Complementary metal-oxide semiconductor
Common mode oscillating system
Complementary mica-oxide silicon
Complementary metal-oxide substrate
E6A14:
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 cannot be compared without first knowing the supply voltage
An FET has low input impedance; a bipolar transistor has high input impedance
The input impedance of FETs and bipolar transistors is the same
E6A15:
What two elements widely used in semiconductor devices exhibit both metallic and nonmetallic characteristics?
Silicon and germanium
Silicon and gold
Galena and germanium
Galena and bismuth
E6A16:
What type of semiconductor material contains fewer free electrons than pure germanium or silicon crystals?
P-type
N-type
Superconductor-type
Bipolar-type
E6A17:
What are the majority charge carriers in N-type semiconductor material?
Free electrons
Holes
Free protons
Free neutrons
E6A18:
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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