AP ECET EEE 2019-10

1.The major cause of creeping in an energy meter is _____________

A. over compensation for friction
B. Mechanical vibrations
C. excessive voltage across the potential coil
D. stray magnetic fields

Answer : over compensation for friction
Explanation:-

2. In a centre tap full wave rectifier, 100v is the peak voltage between the centre tap and one end of the secondary. what is the maximum voltage across the reverse biased diode?

A. 200v
B. 141v
C. 100v
D. 86v

Answer : 200v
Explanation:- The maximum voltage across the reverse biased diode = 2*Vp
=2*100=200V

3. If the reading of two wattmeters are equal and positive in two watt Meter method, the load pf in a balanced 3 phase, 3 wire circuit will be ___________

A. 0
B. 0.5
C. 0.866
D. 1

Answer : 1
Explanation:-

4. A Gate Turn Off (GTO) thyristor has capacity to______________

A. Amplify the gate current
B. Turn-off when positive current pulse is given at the gate
C. Turn off when a gate pulse is given at the gate even though it is reverse biased
D. Turn-off when a negative current pulse is given at the gate

Answer : Turn-off when a negative current pulse is given at the gate
Explanation:-

5.In a UPS the solid state switch normally transfer supply with in _________________

A. 4 ms
B. 30 ms
C. 48 ms
D. 30 s

Answer : 4 msec
Explanation:-

6. Superposition theorem is not applicable for_____________

A. voltage calculations
B. bilateral elements
C. Power calculations
D. passive elements

Answer : Power calculations
Explanation:-

7. In a Wien bridge oscillator, the positive feedback attenuation is _____________

A. 1/3
B. 1/29
C. -29
D. 3

Answer : 1/3
Explanation:-

8.With the increase in speed of a DC motor___________

A. Both back emf as well as line current increases
B. Both back emf as well as line current fall
C. back emf increases but line current falls
D. back emf falls and line current increases

Answer : back emf increases but line current falls
Explanation:-

9. A universal motor is one which has_______________

A. constant speed
B. constant output
C. capability of operating both on ac and dc with comparable performance
D. maximum efficiency

Answer : capability of operating both on ac and dc with comparable performance
Explanation:-

10.Threshold characteristics of a plain impedance relay in a complex Z plane is a _____________

A. circle passing through origin
B. circle with the centre at the origin
C. straight line passing through the origin
D. straight line offset from the origin

Answer : circle with the centre at the origin
Explanation:-