ECET EEE 2010-5

1. A free wheeling diode is placed across the DC load

A) to prevent reversal of load voltage
B) to permit transfer of load current away from the source
C) both 1 and 2
D) to protect the switch

Answer : to permit transfer of load current away from the source
Explanation:-

2. In a three phase full converter, the six SCRs are fixed in intervals of

A) 30 degrees
B) 60 degrees
C) 90 degrees
D) 120 degrees

Answer : 30 degrees
Explanation:-

3. In a single phase fully controlled converter, the number of SCRS conducting during overlap is

A) 1
B) 2
C) 3
D) 4

Answer : 3
Explanation:-

4. A single phase fully controlled converter is a

A) Single quadrant converter
B) Two quadrant converter
C) Four quadrant converter
D) None of the above

Answer : Two quadrant converter
Explanation:-

5. Power factor is equal to

A) Displacement factor - distortion factor
B) (Displacement factor)/ (distortion factor)
C) Displacement factor
D) Distortion factor

Answer : (Displacement factor)/ (distortion factor)
Explanation:-

6. While plugging of a separately excited dc motor, the supply to the armature is

A) Reversed
B) connected to a resistance
C) connected to ac supply
D) none of the above

Answer : Reversed
Explanation:-

7. A three phase AC voltage controller feeding a 3 phase induction motor has an output of

A) constant voltage of variable frequency
B) variable voltage of variable freqeuncy
C) Variable voltage of constant frequency
D) Constant voltage of constant frequency

Answer : variable voltage of variable frequency
Explanation:-

8. Keyboard/display interface

A) 8255
B) 8259
C) 8279
D) 8251

Answer : 8259
Explanation:-

9. The 8051 micro controller is of pin package and a processor

A) 30,1 byte
B) 20, 1 byte
C) 40, 8 byte
D) 60, 8 byte

Answer : 40, 8 byte
Explanation:-

10. In 8051, which interrupt has priority?

A) IE1
B) TFO
C) IEO
D) TFI

Answer : IE1
Explanation:-