This set of FACTS Multiple Choice Questions & Answers (MCQs) focuses on “Characteristics and Requirements of Power Electronic Devices”.
1. The commutation techniques employed in turning-off thyristors are based on the assumptions ________
a) holding current is zero and load draws a constant current
b) holding current is zero and load draws a variable current
c) holding current is non-zero and load draws a constant current
d) holding current is non-zero and load draws a variable current
View Answer
Explanation: The commutation techniques employed in turning-off thyristors are based on the assumptions: holding current is zero and load draws a constant current. Different commutation techniques are available for turning off a thyristor. As per the design requirements, the type of commutation technique is adopted.
2. A transistor with emitter junction forward biased and collector junction reverse biased, is in its ________ mode.
a) saturation
b) inverted
c) cut-off
d) active
View Answer
Explanation: A transistor with emitter junction forward biased and collector junction reverse biased, is in its active mode. In this active region, it can act as an amplifier. Power dissipation is maximum in active mode.
3. A transistor with emitter junction reverse biased and collector junction forward biased is in its ________ mode.
a) saturation
b) inverted
c) cut-off
d) active
View Answer
Explanation: A transistor with emitter junction reverse biased and collector junction forward biased is in its inverted mode. Inverted mode is hardly used as the current gain in this region is very low.
4. A transistor with both emitter junction and collector junction reverse biased, is in its ________ mode.
a) saturation
b) inverted
c) cut-off
d) active
View Answer
Explanation: A transistor with emitter junction forward biased and collector junction reverse biased, in its cut-off mode. In this cut-off region, it can act as a switch. Power dissipation is minimum in cut-off mode.
5. A transistor with both emitter junction and collector junction forward biased is in its ________ mode.
a) saturation
b) inverted
c) cut-off
d) active
View Answer
Explanation: A transistor with both emitter junction and collector junction forward biased is in its saturation mode. In this saturation region, it can act as a switch. Power dissipation is minimum in saturation mode.
6. In BJT the active operating region is ________
a) linear
b) non – linear
c) sinusoidal
d) non – sinusoidal
View Answer
Explanation: In BJT the active operating region is linear. The analysis of a BJT requires both dc and ac analysis, especially in the active region. This is because both ac and dc components are present in any electronic amplifier.
7. For a BJT in active region, the collector current depends on emitter voltage.
a) True
b) False
View Answer
Explanation: For a BJT in active region, the collector current DOES NOT depend on emitter voltage. Actually it depends on the base current. The base-emitter junction is kept forward biased in active mode.
8. The input resistance is highest in ________ of the transistor amplifier.
a) common emitter configuration
b) common collector configuration
c) any configuration
d) common base configuration
View Answer
Explanation: The input resistance is highest in common collector configuration of the transistor amplifier. CC amplifier is commonly not used for amplification. It cannot used for matching a very low impedance source.
9. MNOS stands for ________
a) Metal Neon Oxide Semiconductor
b) Metal Nitrous Oxide Semiconductor
c) Metal Negative Oxide Semiconductor
d) Metal Nitride Oxide Semiconductor
View Answer
Explanation: MNOS stands for metal nitride oxide semiconductor (or silicon). Basically MNOS is a variety of MOSFET. In MNOS, the oxide layer of MOSFET is replaced by a double layer of nitride and oxide, hence the name.
10. JFET stands for ________
a) Junction Forward Effect Transistor
b) Jute Field Effect Transistor
c) Junction Field Effect Transistor
d) Junction Field Effect Transducer
View Answer
Explanation: JFET stands for junction field effect transistor. It has three terminals like MOSFET. However, JFET employs a reverse biased p–n junction to separate the gate terminal from the body.
11. TFET stands for ________
a) Tunnel Forward Effect Transistor
b) Tunnel Field Effect Transistor
c) Tunnel Field Effect Transistor
d) Tunnel Field Effect Transducer
View Answer
Explanation: TFET stands for tunnel field effect transistor. TFET is actually an experimental element. The structure of TFET is very alike to MOSFET. However, these devices exhibit different fundamental switching mechanism.
12. MESFET is the abbreviation of ________
a) Metal Semiconductor Field Effect Transistor
b) Metal Semiconductor Field Effect Thyristor
c) Metal Semi-active Field Effect Transistor
d) Metal Semi-passive Field Effect Transistor
View Answer
Explanation: MESFET is the abbreviation of Metal Semiconductor Field Effect Transistor. Structurally the MESFET is different from JFET. MESFET employs Schottky barrier to replace the p–n junction of the JFET.
13. A BJT exhibits a relatively low gain–bandwidth product compared to that of an FET.
a) True
b) False
View Answer
Explanation: A BJT does not exhibit a relatively low gain–bandwidth product compared to that of an FET. It is an FET that exhibits a relatively low gain–bandwidth product compared to that of a BJT. The gain–bandwidth product for any amplifier is obtained by multiplying the amplifier’s bandwidth with its gain at which the bandwidth is measured.
14. CMOS devices have high noise problems.
a) True
b) False
View Answer
Explanation: CMOS devices DO NOT have high noise problems. CMOS devices are actually high noise-immuned. Also they exhibit low static power consumption.
15. CMOS stands for ________
a) Complementary Metal Oxide Semiconductor
b) Common Metal Oxide Semiconductor
c) Conjugated Metal Oxide Semiconductor
d) Convoluted Metal Oxide Semiconductor
View Answer
Explanation: CMOS stands for complementary metal oxide semiconductor. CMOS is a variety of MOSFET fabrication process. This technology utilizes complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions.
Sanfoundry Global Education & Learning Series – Flexible AC Transmission System (FACTS).
To practice all areas of Flexible AC Transmission System (FACTS), here is complete set of 1000+ Multiple Choice Questions and Answers.
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