Power Electronics MCQs – Power Electronics Objective Multiple Choice Questions

Power Electronics combines the solid-state electronic components with control and power systems so as to control the electric power systems, drives, and industrial controls. While modern switchyards and substations heavily rely on power electronics, it is crucial to develop a clear image of the entire subject. In this regard, Electrical Engineering XYZ shares power electronics MCQs which are important for electrical jobs, competitive tests, university exams.

The device which performs DC-DC conversion

The device which performs DC-DC conversion:

1. Inverter
2. Rectifier
3. Chopper
4. Switch

Correct answer: 3. Chopper

Explanation: Chopper is an electrical device which converts dc to dc conversion.

• Inverter: An inverter is a power electronics device that converts DC (Direct Current) to AC (Alternating Current). It is commonly used in applications where AC power is required, such as in homes and electrical grids.
• Rectifier: The rectifier is also a power electronic device that performs conversion between AC to DC. It is often used in applications where DC power is needed, such as in electronic devices and power supplies.
• Chopper: A chopper is a device that performs DC-DC conversion. It is used to convert one DC voltage level to another DC voltage level. Choppers use semiconductor switches (typically MOSFETs or IGBTs) to control the flow of current and voltage in order to regulate and modify the DC output. Choppers are commonly used in applications like electric vehicles, renewable energy systems, and adjustable-speed drives.
• Switch: A switch is a generic term used to describe a device or component that can control the flow of electric current. It can be used in various contexts, including both AC and DC circuits. While a switch can be part of a chopper circuit, it does not necessarily refer specifically to a device that performs DC-DC conversion on its own.

Hence 3. Chopper is correct answer.

DIAC has how many terminals

The DIAC is a:

1. One terminal device
2. Two terminal device
3. Three-terminal device
4. Four terminal device

Correct answer: 2. Two terminal device

Explanation: The DIAC (Diode for Alternating Current) is a semiconductor device that is used mainly as a triggering device for other semiconductor switching devices, notably the TRIAC. A DIAC can be considered a type of thyristor without a gate terminal, and it functions as a bidirectional trigger diode which conducts current only after its breakover voltage has been exceeded momentarily.

The DIAC has three layers of semiconductor material, but effectively, it has only two terminals. These terminals are usually referred to simply as the anode and cathode, which might be confusing as it suggests a similarity to a diode, which is a two-terminal device. Despite having three layers, the DIAC does not have a gate terminal like the TRIAC or other thyristors.

The TRIAC is

The TRIAC is:

1. An SCR
2. Made up of three DIAC’s
3. Is alike a bi-directional SCR
4. None of these

Correct answer: 3. Is alike a bi-directional SCR

Explanation: The structure of TRIAC matches two SCR’s which are joined back to back in a parallel fashion. Thus we can relate a TRIAC with a bi-directional SCR.

Number of PN junctions on a thyristor

A thyristor has:

1. One pn junction
2. Two pn junctions
3. Three pn junctions
4. Four pn junctions

Correct answer: 3. Three pn junctions

Explanation: A thyristor is a semiconductor device commonly used in power control applications. It is a four-layer, three-terminal device that acts as a switch, allowing current to flow in one direction when triggered. The two main types of thyristors are silicon-controlled rectifiers (SCRs) and triacs.

Number of Gate terminals on SCS

The SCS has:

1. Single gate terminal
2. Two gate terminals
3. Three gate terminals
4. Four gate terminals

Correct answer: 3. Two gate terminals

Explanation: A silicon-controlled switch, or SCS, is essentially an SCR with an extra gate terminal. Typically, the load current through an SCS is carried by the anode gate and cathode terminals, with the cathode gate and anode terminals sufficing as control leads.

The figure below displays schematic diagram, physical structure and equivalent schematic of SCS.

PUT stands for

PUT stands for:

1. Programmable Unijunction Transistor
2. Positive Unijunction Transistor
3. Photoconductive Unijunction Transistor
4. Pi Unijunction Transistor

Correct answer: 1. Programmable Unijunction Transistor

Explanation: A Programmable Unijunction Transistor (PUT) is similar to a standard unijunction transistor but with an added feature that allows the intrinsic stand-off ratio to be set externally by two resistors. This makes the PUT a versatile component because its switching characteristics can be adjusted according to the needs of the circuit. The other options—Positive Unijunction Transistor, Photoconductive Unijunction Transistor, and Pi Unijunction Transistor—do not correspond to the standard abbreviations or names used in electronics.

Forced commutation on SCS can be achieved by

Forced commutation on SCS can be achieved by:

1. Shorting anode and cathode terminals
2. By Applying a negative voltage between anode and cathode
3. Both of these
4. None of these

Correct answer: 3. Both of these

The correct statement about SCR

The correct statement about SCR:

1. SCR is not a rectifier
2. A single SCR can’t be used in full ac control
3. SCR is not used commonly because it is very expensive
4. GTO is a variant of SCR

Correct answer: 2. A single SCR can’t be used in full ac control

A DIAC conducts current in

A DIAC conducts current in:

1. One direction
2. Two directions

Correct answer: 2. Two directions

The LASCR is

The LASCR is:

1. A laser activated SCR
2. A light-activated SCR
3. Lithium anode SCR
4. None of these

Correct answer: 2. A light-activated SCR

Sort the correct statement about DIAC and TRIAC

Sort the correct statement about DIAC and TRIAC:

1. Both are bilateral devices
2. TRIAC is bilateral, but DIAC is unilateral
3. DIAC is bilateral, but TRIAC is unilateral
4. Both are unilateral devices

Correct answer: 1. Both are bilateral devices

Which one the following is not a thyristor

Which one the following is not a thyristor:

1. SCS
2. UJT
3. DIAC
4. TRIAC

Correct answer: 2. UJT

The device which performs dc-ac conversion

The device which performs dc-ac conversion:

1. Inverter
2. Rectifier
3. Chopper
4. Switch

Correct answer: 1. Inverter

The SCS is a _____ terminal thyristor that has _____ gate terminals

The SCS is a _____ terminal thyristor that has _____ gate terminals.

1. Two, two
2. Two, four
3. Four, two
4. Four, one

Correct answer: 3. Four, two

The SCS is turned on by

The SCS is turned on by:

1. Applying a negative pulse on anode gate
2. Applying a positive pulse on anode gate
3. Applying a negative pulse on cathode gate
4. None of these

Correct answer: 1. Applying a negative pulse on anode gate

UJT has ______ pn junction/junctions

UJT has ______ pn junction/junctions:

1. Single
2. Two
3. Three
4. Four

Correct answer: 1. Single

Which one of the following is not a thyristor

Which one of the following is not a thyristor:

1. PUT
2. UJT
3. SCS
4. DIAC

Correct answer: 2. UJT

LASCR is a

LASCR is a:

1. Rectifier
2. Thyristor
3. Both of these
4. None of these

Correct answer: 3. Both of these

The device that has no gate terminal

______ has/have no gate terminal:

1. DIAC
2. TRIAC
3. Both of these
4. None of these

Correct answer: 1. Diac

Explanation: The DIAC has no gate terminal

• Diac: A diac is a two-terminal semiconductor device that is used to trigger and control the conduction of alternating current (AC). It is a bidirectional device, meaning it can conduct current in both directions. The diac does not have a gate terminal. It is typically used in power electronics applications such as triggering triacs and controlling dimmer circuits.
• Triac: A triac is a three-terminal semiconductor device that is also used for controlling AC power. It is similar to a thyristor but can conduct current in both directions. The triac has three terminals: an MT1 (main terminal 1), an MT2 (main terminal 2), and a gate terminal. The gate terminal is used to control the triggering of the device.

The method which can be used to latch Shockley diode

The method which can be used to latch Shockley diode:

1. Exceed the critical rate of voltage rise from anode to cathode
2. Exceed the breakover voltage from anode to cathode
3. Both of these
4. None of these

Correct answer: 3. Both of these

A thyristor has

A thyristor has:

1. One pn junction
2. Two pn junctions
3. Three pn junctions
4. Four pn junctions

Correct answer: 3. Three pn junctions

The SCS has

The SCS has:

1. Single gate terminal
2. Two gate terminals
3. Three gate terminals
4. Four gate terminals

Correct answer: 2. Two gate terminals

Forced commutation on SCS can be achieved by

Forced commutation on SCS can be achieved by:

1. Shorting anode and cathode terminals
2. By Applying a negative voltage between anode and cathode
3. Both of these
4. None of these

Correct answer: 3. Both of these

The correct statement about SCR

The correct statement about SCR:

1. SCR is not a rectifier
2. A single SCR can’t be used in full ac control
3. SCR is not used commonly because it is very expensive
4. GTO is a variant of SCR

Correct answer: 3. A single SCR can’t be used in full ac control

PUT stands for

PUT stands for:

1. Programmable Unijunction Transistor
2. Positive Unijunction Transistor
3. Photoconductive Unijunction Transistor
4. Pi Unijunction Transistor

Correct answer: 1. Programmable Unijunction Transistor

A DIAC conducts current in

A DIAC conducts current in:

1. One direction
2. Two directions

Correct answer: 2. Two direction

The LASCR is

The LASCR is:

1. A laser activated SCR
2. A light-activated SCR
3. Lithium anode SCR
4. None of thes

Correct answer: 2. A light-activated SCR

Sort the correct statement about DIAC and TRIAC

Sort the correct statement about DIAC and TRIAC:

1. Both are bilateral devices
2. TRIAC is bilateral, but DIAC is unilateral
3. DIAC is bilateral, but TRIAC is unilateral
4. Both are unilateral devices

Correct answer: 1. Both are bilateral devices

Which one the following is not a thyristor

Which one the following is not a thyristor:

1. SCS
2. UJT
3. DIAC
4. TRIAC

Correct answer: b. UJT

The device which performs DC-AC conversion:

1. Inverter
2. Rectifier
3. Chopper
4. Switch

Correct answer: 1. Inverter

The SCS has how many gate terminals

The SCS has how many gate terminals:

1. Two, two
2. Two, four
3. Four, two
4. Four, one

Correct answer: 3. Four, two

The SCS is turned on by

The SCS is turned on by:

1. Applying a negative pulse on anode gate
2. Applying a positive pulse on anode gate
3. Applying a negative pulse on cathode gate
4. None of these

Correct answer: a. Applying a negative pulse on anode gate

UJT has how many PN junctions

UJT has how many PN junctions

1. One
2. Two
3. Three
4. Four

Correct answer: 1. One

Which one of the following is not a thyristor

Which one of the following is not a thyristor:

1. PUT
2. UJT
3. SCS
4. DIAC

Correct answer: 2. UJT

LASCR is a

LASCR is a:

1. Rectifier
2. Thyristor
3. Both of these
4. None of these

Correct answer: 3. Both of these

Which of following has no gate terminal

Which of following has no gate terminal:

1. Diac
2. Triac
3. Both of these
4. None of these

Correct answer: 1. Diac

The method which can be used to latch Shockley diode

The method which can be used to latch Shockley diode:

1. Exceed the critical rate of voltage rise from anode to cathode
2. Exceed the breakover voltage from anode to cathode
3. Both of these
4. None of these

Correct answer: 3. Both of these

Inverter performs conversion from

a. Inverter performs conversion from:

1. AC to DC
2. AC to AC
3. DC to DC
4. DC to AC

Answer: 4. DC to AC

All of these are types of power diodes

The output voltage in a ____________ regulator is always lower than input voltage

b. The output voltage in a ____________ regulator is always lower than input voltage:

1. Boost
2. Buck
3. Both of these
4. None of these

Answer: 4. Buck

SCR is a ________________ device

c. SCR is a ________________ device:

1. Uni-directional
2. Bi-directional
3. Tri-directional
4. Quad-directional

Answer: 1. Uni-directional

The load voltage in a four quadrant converter is

d. The load voltage in a four quadrant converter is:

1. Positive
2. Negative
3. Both of these
4. None of these

Answer: 3. Both of these

Triac is a _______________ device which __________ a Gate terminal

e. Triac is a _______________ device which __________ a Gate terminal:

1. Unilateral, contains
2. Bilateral, contains
3. Unilateral, does not contain
4. Bilateral ,does not contain

Answer: 2. Bilateral, contains

A DC Chopper is actually a

f. A DC Chopper is actually a:

1. DC to AC Converter
2. AC to DC Converter
3. AC to DC and then Back to DC converter
4. DC to DC Converter

Answer: 4. DC to DC Converter

A MOSFET is

g. A MOSFET is:

1. A Power transistor
2. A type of diode
3. A power diode
4. Not a transistor

Answer: 1. A Power transistor

In case of an ideal power diode, the leakage current flows from

In case of an ideal power diode, the leakage current flows from

1. Anode to cathode
2. Cathode to anode
3. Both of above
4. None of these

Correct answer: 4. None of these

Explanation: In case of ideal power diode, the Leakage current does not flow.

The thyristor can be also called as

The thyristor can be also called as

1. AC Switch
2. DC Switch
3. Both of these
4. None of these

Correct answer: 2. DC Switch

Explanation: A thyristor is a unidirectional device and it conducts current in one direction only. However, unlike a diode, the thyristor can operate as either an open circuit switch or as a rectifying diode depending on way the thyristor gate is triggered. In simple words thyristors can operate in the switching mode and can be thought as DC Switch.

Which of following is type of power transistor

Which of following is type of power transistor:

1. BJTs
2. MOSFETs
3. IGBTs
4. All of these

Correct answer: 4. All of these

SCRs are used in series to meet

SCRs are used in series to meet

1. Low current demand
2. Low voltage demand
3. High current demand
4. High voltage demand

Correct answer: 4. High voltage demand

Leakage current flows through the thyristor during

Leakage current flows through the thyristor during:

1. Forward blocking mode
2. Reverse blocking mode
3. Both of above
4. None of these

Correct answer: 3. Both of above

Explanation:

In forward blocking mode junction J₂ and in reverse blocking mode

Of following, the device that does not belong to the transistor family is

Of following, the device that does not belong to the transistor family is

1. BJT
2. GTO
3. IGBT
4. MOSFET

Correct Answer: 2. GTO

Explanation: GTO or gate turn off switch (GTO) belongs to Thyristors. Thyristors are a broad classification of bipolar-conducting semiconductor devices having four (or more) alternating N-P-N-P layers. Thyristors include: silicon controlled rectifier (SCR), TRIAC, gate turn off switch (GTO), silicon controlled switch (SCS), AC diode (DIAC), unijunction transistor (UJT), programmable unijunction transistor (PUT). Continue reading full article on Thyristors.

Dynamic equalizing circuit is used for

Dynamic equalizing circuit is used for

1. Equal division of voltage across each thyristor
2. Equal division of current through each thyristor in parallel
3. Equal division of voltage across each thyristor in parallel
4. Equal division of current through each thyristor in series

Correct answer: 1. Equal division of voltage across each thyristor

Explanation: Dynamic equalizing circuit is a snubber circuit that is used to equalize the voltage division under transient condition.

Recommended reading: Shockley Diode Construction and Working

IGBT combines the advantages of

IGBT combines the advantages of

1. BJTs and SITs
2. SITs and MOSFETs
3. BJTs and MOSFETs
4. None of these

Correct answer: 3. BJTs and MOSFETs

Explanation: IGBT combines the advantage of both BJTs and MOSFETs: Click here to Read ElectricalEngineering.XYZ’s article on MOSFET. IGBT possesses high input impedance like a MOSFET and has low on state power loss as in a BJT.

Which of following devices has highest di/dt and dv/dt capability

Which of following devices has highest di/dt and dv/dt capability:

1. GTO
2. SIT
3. SITH
4. SCR

Correct answer: 1. GTO

Explanation:

The static induction is thyristor with a buried gate structure in which the gate electrode are placed in n-base region. They have high di/dt and dv/dt rating. You might like reading Semiconductor Manufacturing Techniques

The SCR is considered as semi controlled device since

The SCR is considered as semi controlled device since

1. It can be turned on but not off with a gate pulse
2. It can be turned off but not on with a gate pulse
3. It conducts only during half cycle of an alternating current wave
4. It can be turned on only during one half cycle of an ac

Correct answer: 1. It can be turned on but not off with a gate pulse

Explanation:

During positive half cycle SCR is in forward blocking mode. By applying gate pulse the SCR can be turned ON.

However, SCR cannot be turned OFF by applying gate pulse. Rather, it automatically turns off when anode current is below the Holding current.

That is the reason SCR is called semi-controlled rectifier.

Which of following doping is done to make a signal diode suitable for high current high voltage applications with minimum losses

Which of following doping is done to make a signal diode suitable for high current high voltage applications with minimum losses

1. A lightly doped n layer is grown between the two p and n layers
2. A lightly doped p layer is grown between the two p and n layers
3. A heavily doped p layer is grown between the two p and n layers
4. A heavily doped n layer is grown between the two p and n layers

Correct answer: 1. A lightly doped n layer is grown between the two p and n layers

See complete list of Power Electronics MCQs

When the PN junction diode is forward biased, the width of the depletion region

When the PN junction diode is forward biased, the width of the depletion region:

1. Decreases
2. Increases
3. Remains constant
4. Increases than decreases

Correct answer: 1. Decreases

Explanation: When a diode is forward biased, the depletion layer narrows down and finally it collapses to allow the flow of electric current.

When reverse breakdown occurs in a diode

When reverse breakdown occurs in a diode

1. Voltage is constant while current increases
2. Voltage increases while current is constant
3. Voltage increases while current also increases
4. Both voltage and current are constant

Correct answer: 1. Voltage is constant while current increases

Certain transistor is operating at the middle of the load line, then a decrease in the current gain would

Certain transistor is operating at the middle of the load line, then a decrease in the current gain would

1. Move the Q point down
2. Move the Q point up
3. Not change the Q point
4. Result in to and fro motion of the Q point

Correct answer: 1. Move the Q point down

The N-channel MOSFET is considered better than the P-channel MOSFET due to

The N-channel MOSFET is considered better than the P-channel MOSFET due to:

1. Faster operation
2. Low noise levels
3. Lower input impedance
4. TTL compatibility

Correct answer: 1. Faster operation

The Thyristor (SCR) is a

The Thyristor (SCR) is a

1. P-N-P device
2. N-P-N device
3. P-N-P-N device
4. None of these

Correct Answer: 3. P-N-P-N device

Explanation: A Silicon-Controlled Rectifier, or SCR, is essentially a Shockley diode with an extra terminal added. This extra terminal is called the gate, and it is used to trigger the device into conduction (latch it) by the application of a small voltage. The figure below displays physical diagram and schematic symbol of SCR.

Read more about SCR in this article

A power transistor is a

A power transistor is a

1. Three terminal, bipolar, current controlled device
2. Three terminal, unipolar, voltage controlled device
3. Two terminal, bipolar, voltage controlled device
4. Two terminal, unipolar, current controlled device

Correct Answer: 1. Three terminal, bipolar, current controlled device

The ratio of collector current to base current in a transistor is known as

The ratio of collector current to base current in a transistor is known as:

1. Alpha
2. Beta
3. Gamma
4. Zeta

Correct answer: 2. Beta

Explanation:

The ratio of collector current to base current, β is the fundamental parameter characterizing the amplifying ability of a bipolar transistor. β is usually assumed to be a constant figure in circuit calculations, but unfortunately this is far from true in practice. As such, manufacturers provide a set of β (or “h_fe”) figures for a given transistor over a wide range of operating conditions, usually in the form of maximum/minimum/typical ratings. It may surprise you to see just how widely β can be expected to vary within normal operating limits. One popular small-signal transistor, the 2N3903, is advertised as having a β ranging from 15 to 150 depending on the amount of collector current. Generally, β is highest for medium collector currents, decreasing for very low and very high collector currents. h_fe is small signal AC gain; h_FE is large AC signal gain or DC gain. Continue Reading at: Top 10 Transistor ratings

The device which performs AC to DC conversion is known as

The device which performs AC to DC conversion is known as:

1. Rectifier
2. Inverter
3. Chopper
4. Cycloconverter

Correct answer: 1. Rectifier

Also See MCQs on SCR here

For a power transistor, if the base current IB is increased keeping VCE constant, then

For a power transistor, if the base current IB is increased keeping VCE constant, then

1. I_c increases
2. I_c decreases
3. I_c remains constant
4. None of these

Correct Answer: 1. I_c increases

The typical value of SCR for modern alternator is

The typical value of SCR for modern alternator is

1. 0.5
2. 1
3. 1.2
4. 1.5

Correct answer: 1. 0.5

In case of a P₁N₁P₂N₂ thyristor, the layer that is less doped

In case of a P₁N₁P₂N₂ thyristor, the layer that is less doped

1. N₁
2. N₂
3. P₁
4. P₂

Correct answer: 1. N₁

A GTO can be turned on by applying

A GTO can be turned on by applying

1. Positive drain signal
2. Positive gate signal
3. Positive source signal
4. ZxNone of these

Correct answer: 2. Positive gate signal

SCR can be protected against thermal conditions by

SCR can be protected against thermal conditions by

1. Using CB and fuse
2. Using equalizing circuit
3. Using heat sink
4. Using snubber circuit

Correct answer: 3. Using heat sink

Which of below mentioned is a two terminal three-layer device

Which of below mentioned is a two terminal three-layer device

1. BJT
2. MOSFET
3. Power diode
4. None of above

Correct answer: 3. Power diode

Which of following are types of Power transistors

Which of following are types of Power transistors

1. BJTs
2. IGBTs
3. MOSFETs
4. All of above

Correct answer: 4. All of above

SCR will be turned off when anode current is

SCR will be turned off when anode current is

1. Less than holding current
2. Less than latching current but greater than holding current and gate signal is 0
3. ZxBoth of above
4. ZyNone of above

Correct answer: 3. ZxBoth of above” “

The power MOSFET has three terminals named as

The power MOSFET has three terminals named as

1. Collector, emitter and base
2. Collector, emitter and gate
3. Drain, source and base
4. Drain, source and gate

Correct answer: 4. Drain, source and gate

A single phase full bridge inverter can be operated in load commutation mode, provided that the load comprises of

A single phase full bridge inverter can be operated in load commutation mode, provided that the load comprises of

1. RL
2. RLC critically damped
3. RLC over damped
4. RLC underdamped

Correct answer: 4. RLC underdamped

As compared to transistor, XYZs have lower on state conduction losses and higher power handling capability

As compared to transistor, XYZs have lower on state conduction losses and higher power handling capability

1. MOSFETs
2. Semi-conductor diodes
3. Thyristor
4. TRIACs

Correct answer: 3. Thyristor

The reliability of a string of SCRs can be measured using

The reliability of a string of SCRs can be measured using

1. Derating factor
2. Factor of safety
3. Reliability factor
4. String efficient

Correct answer: 1. Derating factor

Gate circuit or triggering circuit of a thyristor is

Gate circuit or triggering circuit of a thyristor is

1. Any of above
2. High power circuit
3. Lower power circuit
4. Magnetic circuit

Correct answer: 3. Lower power circuit

During reverse blocking mode of a thermistor

During reverse blocking mode of a thermistor

1. Junction J₁ and J₂ is in forward bias and J₃ is in reverse bias
2. Junction J₁, J₃ is in reverse bias and J₂ is in forward bias
3. Junction J₂ is in reverse bias and J₁, J₃ is in forward bias
4. Junction J₃ is in forward bias and J₁, J₂ in reverse bias

Correct answer: 2. Junction J₁, J₃ is in reverse bias and J₂ is in forward bias

SITH is also known as

SITH is also known as

1. Filled controlled diode
2. Filled controlled rectifier
3. Silicon controlled rectifier
4. None of above

Correct answer: 1. Filled controlled diode

The typical time of rising ranges between

The typical time of rising ranges between

1. 1 – 4 µs
2. 4 – 20 µs
3. 40 – 60 µs
4. 0.015

Correct answer: 1. 1 – 4 µs

Which of below mentioned does not belong to class of power transistors

Which of below mentioned does not belongs to class of power transistors

1. COOLMOS
2. IGBT
3. SITS
4. TRIAC

Correct answer: 4. TRIAC

The latching current of SCR is 20 mA. Its holding current will be

The latching current of SCR is 20 mA. Its holding current will be

1. 10 mA
2. 40 mA
3. 60 mA
4. 95 mA

Correct answer: 1. 10 mA

Which of below mentioned is normally ON device

Which of below mentioned is normally ON device

1. BJT
2. IGBT
3. SIT
4. TRIAC

Correct answer: 3. SIT

Which of following is most appropriate power device for high frequency (>100 KHz) switching application

Which of following is most appropriate power device for high frequency (>100 KHz) switching application

1. BJT
2. Microwave transistor
3. Power MOSFET
4. Schottky diode

Correct answer: 3. Power MOSFET

Which of following is used to protect SCR against over current

Which of following is used to protect SCR against over current

1. CB and fuse
2. Heat sink
3. Snubber circuit
4. Voltage clamping device

Correct answer: 1. CB and fuse

Leakage current flows through the thyristor in which mode

Leakage current flows through the thyristor in which mode

1. Both forward and reverse blocking mode
2. Forward blocking mode
3. Reverse blocking mode
4. None of above

Correct answer: 1. Both forward and reverse blocking mode

Which of below mentioned statement is correct

Which of below mentioned statement is correct

1. SIT is a high power, high frequency device
2. SIT is a high power, high voltage device
3. SIT is a high power, low frequency device
4. SIT is a low power, high frequency device

Correct answer: 1. SIT is a high power, high frequency device

The correct statement regarding charge carrier. During reverse recovery time

The correct statement regarding charge carrier. During reverse recovery time

1. Charge carrier of junction J₁ is swept out
2. Charge carrier of junction J₃ is swept out
3. Both of above
4. None of above

Correct answer: 3. Both of above

The major disadvantage of fast recovery diodes is

The major disadvantage of fast recovery diodes is

1. Doping is carried out
2. Its recovery time is only 5 µs
3. Its recovery time is only 50 µs
4. None of above

Correct answer: 1. Doping is carried out

Anode current in an SCR belongs to

Anode current in an SCR belongs to

1. Electrons only
2. Holes only
3. Either electron or holes
4. Both electron and holes

Correct answer: 2. Holes only

If a large surge current of very short duration flows through a thyristor, then which of the following device will operate to protect the thyristor

If a large surge current of very short duration flows through a thyristor, then which of the following device will operate to protect the thyristor

1. CB
2. Fast acting current limiting device
3. Snubber circuit
4. Voltage clamping device

Correct answer: 2. Fast acting current limiting device

The power semiconductor may undergo damage because of

The power semiconductor may undergo damage because of

1. High di/dt value
2. High dv/dt value
3. Low di/dt value
4. Low dv/dt value

Correct answer: 1. High di/dt value

Resistor is used in Snubber circuit so as to

Resistor is used in Snubber circuit so as to

1. Minimize the charging current
2. Minimize the discharging current
3. Minimize the loss
4. All of these

Correct answer: 2. Minimize the discharging current

IGBT combines the advantages of

IGBT combines the advantages of

1. BJTs and MOSFETs
2. BJTs and SITs
3. SITs and MOSFETs
4. None of above

Correct answer: 1. BJTs and MOSFETs

A single-phase full bridge inverter can operate in load commutation mode provided that load is

A single-phase full bridge inverter can operate in load commutation mode provided that load is

1. RL
2. RLC critically damped
3. RLC overdamped
4. RLC underdamped

Correct answer: 4. RLC underdamped