The maximum DC voltage rating (VRDC) of a power diode is useful for selecting ________________ diodes in a DC-DC chopper.

The i-v characteristics of a power diode for large forward current is __________ .

Forward recovery voltage appears due to higher ohmic drop in the ______________ region of a power diode in the beginning of the Turn On process.

The magnitude of the forward recovery voltage is typically of the order of few ______________ of volts.

For a given forward current the reverse recovery current of a Power Diode ______________ with the rate of decrease of the forward current.

For a given forward current the reverse recovery time of a Power diode ______________ with the rate of decrease of the forward current.

A “snappy” recovery diode is subjected to _________________ voltage over shoot on recovery.

A fast recovery diode has _______________________ reverse recovery current and time compared to a __________________ recovery diode.

A Schottky diode has _______________ forward voltage drop and ______________ reverse voltage blocking capacity.

Schottky diodes have no __________________ transient and very little _________________ transient.

A thyristor is a ________________ carrier semi controlled device.

A thyristor can conduct current in ________________ direction and block voltage in ________________ direction.

A thyristor can be turned ON by applying a forward voltage greater than forward ________________ voltage or by injecting a positive ________________ current pulse under forward bias condition.

To turn OFF a thyristor the anode current must be brought below ________________ current and a reverse voltage must be applied for a time larger than ________________ time of the device.

Inverter grade thyristors have ________________ turn off time compared to a converter grade thyristor.

A Triac operates either in the ________________ or the ________________ quadrant of the i-v characteristics.

For “clean turn ON” of a triac the ________________ of the gate current pulse should be as ________________ as possible.

A Triac is a ________________ minority carrier device

A MOSFET is a ________________ controlled ________________ carrier device.

Enhancement type MOSFETs are normally ________________devices while depletion type MOSFETs are normally ________________ devices.

The gate-source voltage at which the ________________ layer in a MOSFET is formed is called the ________________ voltage.

The Gate-Source capacitance of a MOSFET is the ________________ among all three capacitances.

The Gate-Drain transfer capacitance of a MOSFET has large value in the ________________ region and small value in the ________________ region.

For the same load resistance as the vgE of an IGBT is increased it enters __________________ region.

An IGBT has small __________________ temperature coefficient of on state voltage drop.

From the input side the IGBT behaves essentially as a __________________.

A single phase half wave controlled converter always operates in the ________ conduction mode.

The minimum frequency of the output voltage harmonic in a single phase fully controlled bridge converter is _________ the input supply frequency.

The input displacement factor of a single phase fully controlled bridge converter in the continuous conduction mode is equal to the cosine of the ________ angle.

In the discontinuous conduction mode the load current remains __________ for a part of the input cycle.

In the continuous conduction mode if the firing angle of the converter is increased beyond _________ degrees the converter operates in the _______ mode.

A half controlled converter has better output voltage ___________________ compared to a fully controlled converter.

For the same firing angle and input voltage the half controlled converter gives ___________________ output voltage form factor compared to a fully controlled converter.

At the boundary between continuous and discontinuous conduction the value of the output current at ωt = α is ___________________.

Single phase half controlled converters are most suitable for loads requiring ___________________ voltage and current.

In a three phase fully controlled converter each device conducts for an interval of __________ degrees.

The input ac current of a three phase fully controlled converter contains only _________ harmonics but no _________ harmonic.

In ___________ current dual converter only one converter conducts at any time.

The input current of a three phase half controlled converter does not have ________________ cycle symmetry.

Length of the overlap period depends on the valve of the source inductance and load ______________

The control method used for PWM dc - dc converter is

In case of TRC (Time Ratio Control), _________ is varied

In pulse width modulation scheme, _________ is kept constant

In case of a constant frequency system, Ton = (1/4)T. If the chopping frequency 2 kHz, find the value of Toff.

In the current limit control method, the chopper is switched off when

Find the output voltage for a step-up chopper when it is operated at a duty cycle of 50 % and Vs = 240 V.

In dc choppers, the waveforms for input and output voltages are respectively

If the chopper frequency is 200 Hz and on time is 2 ms, then the duty ratio would be

In a step down chopper, the ratio Vo/Vs is given by

In a single phase voltage source square wave inverter with inductive load, the waveform of the load current will be

A PWM switching scheme is used with a three phase inverter to

In voltage source inverters

A single phase full bridge inverter can operate in load commutation mode if load consists of

A voltage source inverter is normally employed when

Which of the following statements is correct in connection with the inverters?

In an inverter, if the fundamental frequency is 50 Hz, if third harmonic is eliminated, then frequencies of other components in the output voltage wave, in Hz, would be

If in a single phase half bridge inverter, the amplitude of the output voltage is Vo and output power is p, then amplitude in the full bridge inverter will be

Inverter provides the facility of

VSI is having the property of

In single phase full wave ac voltage regulator, varying the firing angle from a to 180 can vary the rms output voltage from

The conduction angle of SCR T1 in a single phase full wave controller is obtained from

Application of ac voltage controller using integral cycle method is in

AC voltage regulator converts

Cycloconverter converts

A cycloconverter can be considered as composed of two converters

Realization of an ideal switch using semiconductor device depends on

The switches used in dc-dc converter operates in

Inverter circuit requires ___________ quadrant switches

Cycloconverter requires ________ quadrant switches

A diode is an

Which of the following is not an active switch?

Which of the following is an active switch?

Which of the following is a two quadrant switch?

The expression for a step-up/step-down chopper with α as the duty cycle and Vs as the dc input voltage is

For a single phase thyristor circuit with R load & firing angle α, the conduction angle can be given by

In three phase semiconverter circuit, __ and __ conduct along with T2.

The TRIAC is most sensitive in the _________ quadrants

In the internal structure of a MOSFET, a parasitic BJT exists between the

In the three-phase bridge inverter, each step consists of