BSNL TTA Last Year Papers

I’m looking for BSNL TTA exam paper here will you please also help me to get the paper so that I can solve it easily?

[pawan]

YA sure buddy I will help you here to get the BSNL TTA exam paper so that you can have idea about the exam.

Here is the exam paper
1. An open loop control system has its

(a) control action independent of the output or desired quantity

(b) controlling action, depending upon human judgment

(c) internal system changes automatically taken care of

(d) both (a) and (b)

(e) all (a),(b) and (c)

2. A servo system must have

(a) feedback system

(b) power amplifier to amplify error

(c) capacity to control position or its derivative

(d) all of these

(e) none of these

3. The major disadvantage of a feedback system may be

(a) Inaccuracy

(b) inefficiency

(c) Unreliability

(d) instability

(e) Insensitivity

4. Properties of a transfer function

(a) It is ratio of two polynomials is S and assumes zero initial conditions

(b) It depends on system elements and not input and output of the system

(c) Coefficients of the powers of S in denominator and numerator are all real constant. The order of denominator is usually greater than or equal to the order of numerator

(d) All of these

(e) It is a function which transfer one physical system into another physical system.

5. The classical analogous of a simple lever is

(a) Capacitor bridge

(b) transformer

(c) mutual inductor

(d) either of these

6. Two blocks G1(s) and G2(s) can be cascaded to get resultant transfer function as

(a) G1(s) + G2(s)

(b) G1(s) / G2(s)

(c) G1(s) G2(s)

(d) 1+G1(s) G2(s)

(e) 1-G1(s)G2(s)

(f) two blocks cannot be cascaded

7. The principles of homogeneity and super position can be applied to

(a) linear time invariant system

(b) non-linear time invariant system

(c) digital control system

(d) both (a) and (b)

8. Pick up the nonlinear system

(a) automatic voltage regulator

(b) d.c. servomotor with high field excitation

(c) temperature control of a furnaces using thermistor

(d) speed control using SCR

(e) all of these

9. Signal flow graph (SFG) is a

(a) polar graph

(b) semi log graph

(c) log log graph

(d) a special type of graph for analyzing modem control system

(e) a topological representation of a set of differential equations

10. Disadvantages of magnetic amplifier

(a) time lag, less flexible, non-sinusoidal waveform

(b) low power consumption and isolation of the active circuit

(c) saturation of the core

(d) all of these

11. Pick up false statement regarding magnetic amplifiers

(a) The gate coil of an ideal magnetic amplifier has either zero or infinite inductance

(b) Resistance of control and gate winding is very small

(c) Magnetic amplifier gas dropping load characteristics

(d) Magnetic amplifiers are not used to control the speed of d.c. shunt motor

(e) Magnetic amplifiers can be used in automatic control of electric drivers of higher rating.

12. High power amplification is achieved by using

(a) push pull amplifier

(b) amplidyne

(c) magnetic amplifier

(d) DC amplifier

(e) D.C. generator

13. Pick up false statement regarding servomotors

(a) The d.c. servomotors are lighter than equivalent a.c. servomotors

(b) The d.c. servomotors develops higher starting and reversing torque than equivalent a.c. servomotor.

(c) A drag cup a.c. servomotor has one windings on stator and other on rotor

(d) Output power of servomotors varies from 1/20 W to 100 W

14. To reduce steady state error

(a) decrease natural frequency

(b) decrease damping

(c) increase damped frequency

(d) increase time constant

(f) increase gain constant of the system

15. A good factor for Mp should be

(a) less than 1

(b) lying between 1.1 and 1.5

(c) more than 2.2

(d) zero

(e) infinity

16. Pick up false statement. Routh-Hurwitz criterion

(a) is used for determining stability of a system

(b) is an algebraic procedure

(c) gives the exact location of roots of the characteristic equation

(d) does not indicate relative degree of stability or instability

17. Which of the following is the time domain method of determining stability of a control system

(a) Bode plot

(b) Nyquist plot

(c) Nicholos chart

(d) Routh-Hurwitz array

(e) Constant M and (fy) locus

(f) Root locus technique

18. The technique which gives transient response quickly as well as stability information is

(a) Nyquist plot

(b) Routh-Hurwitz criteria

(c) Bode plot

(d) Root locus plot

(e) Nichols plot

19. The bandwidth can be increased by use of

(a) phase lag network

(b) phase lead network

(c) both (a) and (b) in cascade

(d) both (a) and (b) in parallel

(e) none of these

20. Nyquist plot is drawn on

(a) semi log graph paper

(b) log log graph paper

(c) polar graph paper

(d) centimeter graph paper