AP ECET EEE 2019-2

1. A RLC Series circuit has f1 and f2 as the half power frequencies and f0 as the resonant frequency. The Quality factor of the circuit is

A. (f1+f2)/2f0
B. (f1-f0)/(f2-f0)
C. f0/(f1-f2)
D. (f1-f2)/f0

Answer : f0/(f1-f2)
Explanation:-
Resonant frequency--f0 and Band width = f1-f2 or f2-f1
Quality factor is defined as ratio of Resonant frequency to the bandwidth
Q=f0/(f1-f2)

2. A power chopper converts

A. AC to DC
B. DC to DC
C. DC to AC
D. AC to AC

Answer : DC to DC
Explanation:-

3. Inside the earth or pit, the earthing rod should be placed

A. Horizontally
B. Vertically
C. Inclined at 45°
D. In any position

Answer : Vertically
Explanation:-

4. The RRRV depends upon the

A. type of the circuit breaker
B. capacitance of the system only
C. Inductance of the system only
D. Inductance and capacitance of the system

Answer : Inductance and capacitance of the system
Explanation:- Rate of Rise of Restriking voltage depends on both Inductance and Capacitance of the system

5.If one of the control springs of permanent magnet moving coil ammeter is broken then, when connected it will read

A. Zero
B. half of the correct value
C. Twice the correct value
D. An infinite value

Answer : Zero
Explanation:-

6. The simplest way of shifting load from one shunt generator to the other operating in parallel is by

A. Adjustment of speeds
B. Adjustment of armature resistances
C. Adjustment of field rheostats
D. Using equalizer connections

Answer : Adjustment of field rheostats
Explanation:-

7. The circuit breaker normally operates

A. When the power is to be supplied
B. When the line is to be tested
C. When the switch is to be put on
D. Whenever fault occurs in the line

Answer : Whenever fault occurs in the line
Explanation:-

8. In a three phase induction motor, starting torque will be maximum when

A. R2=1/X2
B. R2=X2
C. R2=X2^2
D. R2=√X2

Answer : R2=X2
Explanation:-
The starting torque of a three phase induction motor is maximum when rotor resistance is equal to rotor reactance

9. The I/O Ports that are used as address and data for external memory are

A. Ports 1 and 2
B. Ports 1 and 3
C. Ports 0 and 2
D. Ports 0 and 3

Answer : Ports 0 and 2
Explanation:-

10. The armature of DC machine is laminated to reduce

A. The hysterisis loss
B. Eddy current loss
C. The mass
D. The inductance

Answer : Eddy current loss
Explanation:- Eddy current loss can be minimised by Laminating the core of poles and rotor where as for reducing hysteresis loss we use High grade steel