76 lines
3.8 KiB
Markdown
76 lines
3.8 KiB
Markdown
E6A Semiconductor materials and devices: semiconductor materials; bipolar junction transistors; operation and types of field-effect transistors
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- [[E6A01]] (C)
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In what application is gallium arsenide used as a semiconductor material? #card
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- [[A.]] In high-current rectifier circuits
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- [[B.]] In high-power audio circuits
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- [[C.]] In microwave circuits
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- [[D.]] In very low-frequency RF circuits
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- [[E6A02]] (A)
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Which of the following semiconductor materials contains excess free electrons? #card
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- [[A.]] N-type
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- [[B.]] P-type
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- [[C.]] Bipolar
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- [[D.]] Insulated gate
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- [[E6A03]] (C)
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Why does a PN-junction diode not conduct current when reverse biased? #card
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- [[A.]] Only P-type semiconductor material can conduct current
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- [[B.]] Only N-type semiconductor material can conduct current
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- [[C.]] Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
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- [[D.]] Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
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- [[E6A04]] (C)
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What is the name given to an impurity atom that adds holes to a semiconductor crystal structure? #card
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- [[A.]] Insulator impurity
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- [[B.]] N-type impurity
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- [[C.]] Acceptor impurity
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- [[D.]] Donor impurity
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- [[E6A05]] (C)
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How does DC input impedance at the gate of a field-effect transistor (FET) compare with that of a bipolar transistor? #card
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- [[A.]] They are both low impedance
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- [[B.]] An FET has lower input impedance
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- [[C.]] An FET has higher input impedance
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- [[D.]] They are both high impedance
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- [[E6A06]] (B)
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What is the beta of a bipolar junction transistor? #card
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- [[A.]] The frequency at which the current gain is reduced to 0.707
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- [[B.]] The change in collector current with respect to the change in base current
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- [[C.]] The breakdown voltage of the base-to-collector junction
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- [[D.]] The switching speed
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- [[E6A07]] (D)
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Which of the following indicates that a silicon NPN junction transistor is biased on? #card
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- [[A.]] Base-to-emitter resistance of approximately 6 ohms to 7 ohms
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- [[B.]] Base-to-emitter resistance of approximately 0.6 ohms to 0.7 ohms
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- [[C.]] Base-to-emitter voltage of approximately 6 volts to 7 volts
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- [[D.]] Base-to-emitter voltage of approximately 0.6 volts to 0.7 volts
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- [[E6A08]] (D)
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What is the term for the frequency at which the grounded-base current gain of a bipolar junction transistor has decreased to 0.7 of the gain obtainable at 1 kHz? #card
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- [[A.]] Corner frequency
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- [[B.]] Alpha rejection frequency
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- [[C.]] Beta cutoff frequency
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- [[D.]] Alpha cutoff frequency
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- [[E6A09]] (A)
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What is a depletion-mode field-effect transistor (FET)? #card
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- [[A.]] An FET that exhibits a current flow between source and drain when no gate voltage is applied
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- [[B.]] An FET that has no current flow between source and drain when no gate voltage is applied
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- [[C.]] An FET that exhibits very high electron mobility due to a lack of holes in the N-type material
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- [[D.]] An FET for which holes are the majority carriers
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- [[E6A10]] (B)
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In Figure [[E6-1]], which is the schematic symbol for an N-channel dual-gate MOSFET? #card
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- [[A.]] 2
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- [[B.]] 4
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- [[C.]] 5
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- [[D.]] 6
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- [[E6A11]] (A)
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In Figure [[E6-1]], which is the schematic symbol for a P-channel junction FET? #card
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- [[A.]] 1
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- [[B.]] 2
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- [[C.]] 3
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- [[D.]] 6
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- [[E6A12]] (D)
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What is the purpose of connecting Zener diodes between a MOSFET gate and its source or drain? #card
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- [[A.]] To provide a voltage reference for the correct amount of reverse-bias gate voltage
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- [[B.]] To protect the substrate from excessive voltages
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- [[C.]] To keep the gate voltage within specifications and prevent the device from overheating
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- [[D.]] To protect the gate from static damage |