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MCQOPTIONS
This section includes 646 Mcqs, each offering curated multiple-choice questions to sharpen your ENGINEERING SERVICES EXAMINATION (ESE) knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
An open loop TF of a unity feedback system is given by\(G\left( s \right) = \frac{1}{{{{\left( {s + 2} \right)}^2}}}\)The closed loop transfer function will have poles at |
| A. | -2, -2 |
| B. | -2, -1 |
| C. | -2 + j, - 2 - j |
| D. | – 2, 2 |
| Answer» D. – 2, 2 | |
| 102. |
For the mass-spring system shown in the given figure, the transfer function X(s)/F(s) is: |
| A. | 1/(Ms2 + K1 – K2) |
| B. | 1/(Ms2 + K1 + K2) |
| C. | 1/(Ms2 + K1K2) |
| D. | 1/(Ms2 + K1) |
| Answer» C. 1/(Ms2 + K1K2) | |
| 103. |
Insertion of negative feedback in control system affects |
| A. | the transient response to vanish uniformly |
| B. | the transient response to decay very fast |
| C. | no change in transient response |
| D. | the transient response decays at a slow rate |
| Answer» C. no change in transient response | |
| 104. |
In Force-Voltage Analogy |
| A. | Force is analogous to current |
| B. | Mass is analogous to capacitance |
| C. | Velocity is analogous to current |
| D. | Displacement is analogous to magnetic flux linkage |
| Answer» D. Displacement is analogous to magnetic flux linkage | |
| 105. |
Feedback control system are |
| A. | Insensitive to both forward path and feedback path parameter changes |
| B. | Less sensitive to feedback path parameter changes than to forward path parameter changes |
| C. | Less sensitive to forward path parameter changes than to feedback path parameter changes |
| D. | Equally sensitive to forward path and feedback path parameter changes |
| Answer» D. Equally sensitive to forward path and feedback path parameter changes | |
| 106. |
In the force-current analogy, capacitance C corresponds to: |
| A. | Inertia |
| B. | Damper |
| C. | Displacement |
| D. | Velocity |
| Answer» B. Damper | |
| 107. |
How many poles does the following function have?\(F\left( s \right) = \frac{{{s^3} + 2s + 1}}{{{s^2} + 3s + 2}}\) |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 108. |
Negative feedback reduces |
| A. | system stability |
| B. | system gain |
| C. | system stability and gain |
| D. | bandwidth |
| Answer» C. system stability and gain | |
| 109. |
Negative feedback in a closed-loop control system does not |
| A. | Reduce the overall gain |
| B. | Reduce bandwidth |
| C. | Improve disturbance rejection |
| D. | Reduce sensitivity to parameter variation |
| Answer» C. Improve disturbance rejection | |
| 110. |
Following statements are given for control systems:a) Transfer function is a ratio of Laplace transform of output to input considering initial conditions are zero.b) Transfer function is a ratio of Laplace transform of output to input irrespective of initial conditions.c) Error signal is a difference of the reference signal and the feedback signal.d) In the signal flow graph the input is divided by transmittance to obtain the output signal.Which of the following is correct? |
| A. | and c) are correct |
| B. | and c) are correct |
| C. | and d) are correct |
| D. | and d) are correct |
| Answer» B. and c) are correct | |
| 111. |
For the following systemFor X1(s) = 0, transfer function \(\frac{{Y\left( s \right)}}{{{X_2}\left( s \right)}}\)is |
| A. | \(\frac{{s + 1}}{{{s^2}}}\) |
| B. | \(\frac{1}{{s + 1}}\) |
| C. | \(\frac{{s + 2}}{{s\left( {s + 1} \right)}}\) |
| D. | \(\frac{{s + 1}}{{s\left( {s + 2} \right)}}\) |
| Answer» E. | |
| 112. |
Close loop control system is better than the open loop system due to |
| A. | Highest levels of amplification |
| B. | Feedback control |
| C. | Robust design features |
| D. | Easy to manufacture |
| Answer» C. Robust design features | |
| 113. |
In a closed loop system for which the output is the speed of a motor, the output rate control can be used to |
| A. | Limit the speed of the motor |
| B. | Limit the torque of the motor |
| C. | Reduce the damping of the system |
| D. | Limit the acceleration of the motor |
| Answer» B. Limit the torque of the motor | |
| 114. |
If \(f\left( s \right) = \left[ {\frac{{\left( {s - a} \right)\left( {s - b} \right)}}{{\left( {s - c} \right)\left( {s - d} \right)}}} \right]\) the poles of f(s) are: |
| A. | s = a and s = 0 |
| B. | s = c and s = d |
| C. | s = a and s = b |
| D. | s = 0 and s = ∞ |
| Answer» C. s = a and s = b | |
| 115. |
Assuming zero initial condition, the response y(t) of the system given below to a unit step input u(t) is: |
| A. | u(t) |
| B. | (t2/2) u(t) |
| C. | tu(t) |
| D. | e-tu(t) |
| Answer» D. e-tu(t) | |
| 116. |
A thermometer requires 1 minute to indicate 98% of its final response to a step input. If it is a first order system the time constant is |
| A. | 1 minute |
| B. | 0.5 minute |
| C. | 0.25 minute |
| D. | 0.1 minute |
| Answer» D. 0.1 minute | |
| 117. |
Bode magnitude plot is drawn between |
| A. | magnitude of network function and ω |
| B. | dB magnitude and log ω |
| C. | dB magnitude and ω |
| D. | loge (magnitude) and log ω |
| Answer» C. dB magnitude and ω | |
| 118. |
The phase margin and damping ratio have no relation. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 119. |
Consider the following statements about root locus 1. The root locus is symmetrical about real axis.2. If a root locus branch moves along the real axis from an open loop pole to zero or to infinity, this root locus branch is called real root branch.3. The breakaway points of the root locus are the solutions of dK/dS = 0Which statements out of above are correct? |
| A. | 1 and 2 only |
| B. | 1 and 3 only |
| C. | 1, 2 and 3 |
| D. | 2 and 3 only |
| Answer» D. 2 and 3 only | |
| 120. |
For the system in the given figure, the gain margin is |
| A. | 0 |
| B. | low |
| C. | + ∞ |
| D. | none of the above |
| Answer» D. none of the above | |
| 121. |
The slope of log magnitude curve changes by - 40 dB/decade at a certain frequency and the error between asymptote and actual curve is positive. This means that |
| A. | a double pole is present |
| B. | a pair of complex conjugate poles is present |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» C. either (a) or (b) | |
| 122. |
For 0 < M < 1, the centres of M circle lie to the right of origin. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 123. |
Assertion (A): In an automobile the amount of fuel admitted to the engine is adjusted as per the difference between desired and actual speed.Reason (R): The control signal is the amount of fuel to be admitted to the engine. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» C. A is correct but R is wrong | |
| 124. |
For Bode plot of (1 + jωT) has |
| A. | slope of 20 dB/decade and phase angle + tan¯¹ (ωT) |
| B. | slope of - 20 dB/decade and phase angle + tan¯¹ (ωT) |
| C. | slope of 20 dB/decade and phase angle - tan¯¹ (ωT) |
| D. | slope of - 40 dB/decade and phase angle - tan¯¹ (ωT) |
| Answer» B. slope of - 20 dB/decade and phase angle + tan¯¹ (ωT) | |
| 125. |
Assertion (A): A. For a unity feedback system, with G(s) = K/s(s+2) , the settling time of step response is constant for all values of K ≥ 1Reason (R): The real part of the roots for all values of K ≥ 1 are negative. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 126. |
The radius and centre of M circles are given by |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 127. |
A phase lead network with Gc(s) = (s+1/T) / (s+1/aT) where a < 1, gives maximum phase lead at a frequency equal to |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 128. |
While forming Routh's array, the situation of a row of zeros indicates that the system |
| A. | has symmetrically located roots |
| B. | is not sensitive to variations in gain |
| C. | is stable |
| D. | is unstable |
| Answer» B. is not sensitive to variations in gain | |
| 129. |
If the Nyquist plot encircles the (-1 + j0) point clockwise once or more number of times, the system is unstable. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 130. |
In the given figure, P = Pm sin ωt. Then X(s) = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 131. |
A first-order system has a time constant t. For unit ramp input, the steady state error is |
| A. | τ² |
| B. | τ |
| C. | √τ |
| D. | 1/τ |
| Answer» C. √τ | |
| 132. |
If Nyquist plot has a encirclement of (-1 + jo) point, the system is stable if |
| A. | there are no poles of G(s) H(s) in right-half plane |
| B. | there is one pole of G(s) H(s) in right-half plane |
| C. | there is no zeros of G(s) H(s) in right-half plane |
| D. | none of the above |
| Answer» B. there is one pole of G(s) H(s) in right-half plane | |
| 133. |
Assertion (A): In control system velocity error is not an error in velocity but is an error in position due to a ramp input.Reason (R): For a type of system velocity error is zero. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» C. A is correct but R is wrong | |
| 134. |
The gain margin of first and second order systems is infinite. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 135. |
An ac tachometer has a drag cup construction so that |
| A. | rotor inertia is low |
| B. | rotor body is conducting |
| C. | rotor is easy to fabricate |
| D. | both (a) and (b) |
| Answer» E. | |
| 136. |
For the system in the given figure G varies slightly, the ratio of open loop sensitivity to closed loop sensitivity is |
| A. | 1 : (1 + GH) |
| B. | 1 : (1 + GH)¯¹ |
| C. | 1 : (1 - GH) |
| D. | 1 : (1 - GH)¯¹ |
| Answer» C. 1 : (1 - GH) | |
| 137. |
Assertion (A): For an underdamped system with damping ratio ξ, the maximum overshoot is e-ξπ/(1-ξ²)^0.5Reason (R): Peak time of a second order under damped system = π/ωd where ωd is frequency of damped oscillations. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» C. A is correct but R is wrong | |
| 138. |
If zeros at infinity are included in the count, the number of zeros of G(s) H(s) is |
| A. | equal to number of poles |
| B. | one more than the number of poles |
| C. | one less than the number of poles |
| D. | none of the above |
| Answer» B. one more than the number of poles | |
| 139. |
The purpose of series quadrature windings in amplidyne is to |
| A. | neutralize the effect of armature reaction |
| B. | reduce commutation difficulties |
| C. | increase the gain |
| D. | increase response time |
| Answer» B. reduce commutation difficulties | |
| 140. |
Assertion (A): When performance specifications are given in term of transient response characteristics, root locus method is a suitable method.Reason (R): When performance specifications in terms of state variables are given, modern control methods can be used. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» C. A is correct but R is wrong | |
| 141. |
Assertion (A): Increasing the system gain improves steady state behaviour but may result in instability.Reason (R): A compensator is inserted into a system to ensure specified performance. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» C. A is correct but R is wrong | |
| 142. |
For the system of the given figure, the closed loop poles are at |
| A. | 0 and -4 |
| B. | -2 ± j√6 |
| C. | 2 ± j√6 |
| D. | -3 ± j√8 |
| Answer» C. 2 ± j√6 | |
| 143. |
One advantage of using polar plot is that it depicts the frequency response characteristics over the entire frequency. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 144. |
For the block diagram of the given figure, the equation describing system dynamics is |
| A. | (1 + RCs) Δθ0(s) = Δθi(s) + R Δ H(s) |
| B. | (1 + RCs) [ΔH(s)] = Δθ(s) - Δθ0(s) |
| C. | (1 + RCs) Δθ0(s) = RΔ H(s) - Δ θi(s) |
| D. | (1 + RCs) Δθi(s) = Δ H(s)[R] - Δθ0(s) |
| Answer» B. (1 + RCs) [ΔH(s)] = Δθ(s) - Δθ0(s) | |
| 145. |
In a proportional plus integral control action |
| A. | proportional gain Kp is adjustable but integral time Ti is constant |
| B. | proportional gain Kp is adjustable but integral time Ti is adjustable |
| C. | both proportional gain Kp and integral time Ti are adjustable |
| D. | both proportional gain Kp and integral time Ti are constant |
| Answer» D. both proportional gain Kp and integral time Ti are constant | |
| 146. |
For a type 1 system and unit parabolic input, the steady state error is |
| A. | 0 |
| B. | ∞ |
| C. | 1 |
| D. | 1/Kv |
| Answer» C. 1 | |
| 147. |
For the given figure, the transfer function X(s)/P(s) = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 148. |
For the system in the given figure the root locus |
| A. | is on real axis between points s = -1 and s = -3.6 |
| B. | is on real axis between points s = 0 and s = -1 |
| C. | is on real axis between points s = -3.6 and s = ∞ |
| D. | is on real axis between points s = 0 and s = -3.6 |
| Answer» B. is on real axis between points s = 0 and s = -1 | |
| 149. |
For a feedback system given below, the velocity error constant Kv is given by |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 150. |
A compensating network has Gc(s) = (1+αTs)/(1+Ts) . If it is a phase lag circuit the value of a should be |
| A. | 0 |
| B. | between 0 and 1 |
| C. | 1 |
| D. | more than 1 |
| Answer» C. 1 | |