In a 3 phase full converter, the instantaneous output voltage can have negative

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Question
In a 3 phase full converter, the instantaneous output voltage can have negative part if
Options
A. firing angle is less than 60�
B. firing angle is less than 90�
C. firing angle is more than 60�
D. firing angle is more than 90�

Correct Answer

firing angle is more than 60�

More questions

3. The application of magnetic field to superconducting material
Options
A. increases transition temperature
B. decreases transition temperature
C. has no effect on transition temperature
D. may increase or decrease the transition temperature

4. When an electric field E is applied to solid and liquid insulating materials, the internal field E_i acting at the location of atom is such that
Options
A. E_i = E
B. E_i > E
C. E_i < E
D. E_i may be equal to or less than E

5. A capacitor can be represented by a capacitance and resistance in parallel. For a good capacitor, this parallel resistance should be
Options
A. negligible
B. low
C. high
D. very high

6. A dc separately excited motor has a constant field current. The armature is fed from a single phase supply through a semi-converter. When a = 0, speed is 600 rpm. If a = 90�, the speed is likely to be
Options
A. about 300 rpm
B. about 150 rpm
C. about 75 rpm
D. about zero

7. A thyristor has maximum allowable junction temperature of 110� C and the ambient temperature is 40�C, If the maximum internal power dissipation is 50 W, the thermal resistance is
Options
A. 2� C/W
B. 1.4� C/W
C. 0.7�C/W
D. 2.2� C/W

8. A 0.5 ?F capacitor is connected across a 10 V battery. After a long time, the circuit current and voltage across capacitor will be
Options
A. 0.5 A and 0 V
B. 0 A and 10 V
C. 20 A and 5 V
D. 0.05 A and 5 V

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