ECET EEE 2012-8

1. The output voltage of a single phase bridge inverter is

A. square wave
B. sinusoidal wave
C. constant dc
D. Triangular wave

Answer : B. sinusoidal wave
Explanation:-

2. Two quandrant operation of dc motor can be obtained if it is fed from a

A. uncontrolled converter
B. Half controlled converter
C. Half wave converter
D. Fully controlled converter

Answer : C. Half wave converter
Explanation:-

3. For controlling the speed of a 3-phase induction motor V/F ratio is maintained constant for

A. Constant air gap flux
B. Constant reactance
C. varying the air gap flux
D. Variable resistance

Answer : C. varying the air gap flux
Explanation:-

4. 8051 microcontroller has _____ data lines and _____ address lines

A. 16,8
B. 8,8
C. 8,16
D. 16,20

Answer : C. 8,16
Explanation:-

5. Which of the following instruction is not a data transfer instruction?

A. XCH
B. PUSH
C. ADD
D. MOV

Answer : A. XCH
Explanation:-

6. Internal memory of 8051 micro controller consists of

A. 128 bytes of RAM, 2K bytes of ROM
B. 4K bytes of RAM, 128 bytes of ROM
C. 2K bytes of RAM, 128 bytes of ROM
D. 128 bytes of RAM, 4K bytes of ROM

Answer : B. 4K bytes of RAM, 128 bytes of ROM
Explanation:-

7. The highest priority interrupt is

A. TF1
B. IE1
C. TF0
D. IE0

Answer : D. IE0
Explanation:-

8. Percentage voltage regulation of a transmission line is given by

A. (Es-Er)/Er*100
B. (Er-Es)/Er*100
C. (Es-Er)/Es*100
D. (Er-Es)/Es*100

Answer : D. (Er-Es)/Es*100
Explanation:-

9. In a main line service of electric traction system _______

A. distance between two stops is vey small
B. Acceleration and retardation periods are small
C. Free running and coasting periods are short
D. Acceleration and retardation periods are long

Answer : D. Acceleration and retardation periods are long
Explanation:-

10. For SCR, dv/dt protection is achieved by connecting _______

A. L in series with SCR
B. RL in series with SCR
C. RC in series with SCR
D. RC in parallel with SCR

Answer : B. RL in series with SCR
Explanation:-