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.Management Sciences
Category: Power Electronics
In reverse blocking mode of a thyristor______?
A. junction J2 is in reverse bias and J1, J3 is in forward bias.
B. junction J3 is in forward bias and J1, J2 in reverse bias.
C. junction J1, J3 is in reverse bias and J2 is in forward bias.
D. junction J1 and J2 is in forward bias and J3 is in reverse bias.
The on – state voltage drop of IGBT consists of__________?
A. Drop across the collector junction
B. Drop across the drift region
C. Drop across MOSFET portion
D. All of these
A modern power semiconductor device that combines the characteristic of BJT and MOSFET is_____________?
A. IGBT
B. FCT
C. MCT
D. GTO
Very large values of modulation index (greater than 3.24) lead to___________?
A. Square AC output voltage
B. Sine AC output voltage
C. Triangular AC output voltage
D. Trapezoidal AC output voltage
For an SCR gate – cathode characteristic is a straight line of 130. For triggered source volume of 15 V and allowable gate power dissipation of 0.5 W compute the gate source resistance_____?
A. 111.9 Ω.
B. 11.19 Ω.
C. 108 Ω.
D. 115 Ω
A thyristor is basically________?
A. PNPN device
B. A combination of diac and triac
C. A set of SCRs
D. A set if SCR,diac and triac
Under normal operating condition voltage clamping device offers impedance of_________?
A. high value.
B. low value.
C. zero value.
D. moderate value.
A GTO can be turned on by applying___________?
A. Positive gate signal
B. Positive drain signal
C. Positive source signal
D. None of these
Unipolar modulation is generally used in____________?
A. AC – AC converters
B. AC – DC converters
C. DC – AC converters
D. DC – DC converters
If the anode current is 800 A, then the amount of current required to turn off the GTO is about____________?
A. 20 A
B. 200 A
C. 600 A
D. 400 A
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