MCQOPTIONS
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MCQOPTIONS
This section includes 519 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
The frequency at which phase angle is 180° is called |
| A. | phase crossover frequency |
| B. | stability limit frequency |
| C. | frequency of limited stability |
| D. | gain margin frequency |
| Answer» B. stability limit frequency | |
| 102. |
A system has .If x(t) = t2, Y(s) is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» D. [D]. | |
| 103. |
A system has its two poles on the negative real axis and one pair of poles lies on jω axis. The system is |
| A. | stable |
| B. | unstable |
| C. | limitedly stable |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 104. |
For the block diagram of in the given figure, the transfer function C(s)/R(s) is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» C. [C]. | |
| 105. |
In liquid flow system the capacitance of a water tank is defined as |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | none of the above |
| Answer» B. [B]. | |
| 106. |
For the system of the given figure the transfer function = |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» C. [C]. | |
| 107. |
For the equation where Q is heat energy, Ct is thermal capacitance and θ is temperature, the analogous electrical equation is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | none of the above |
| Answer» B. [B]. | |
| 108. |
For the equation where Q is heat energy Gt is thermal conductance and θ is temperature, analogous electrical equation is |
| A. | i = G(v1 - v2) |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» B. [B]. | |
| 109. |
Nichol’s chart is symmetric about – 180° axis. |
| A. | rue |
| B. | alse |
| Answer» B. alse | |
| 110. |
Which of the following can be used as a rotating amplifier in a control system?1. Amplidyne2. Separately excited dc generator3. Synchro4. Self excited dc generator |
| A. | and 4 |
| B. | and 2 |
| C. | , 2 and 3 |
| D. | ll |
| Answer» C. , 2 and 3 | |
| 111. |
Assertion (A): F(s) is valid throughout s plane except at poles of F(s).Reason (R): £[f1(t) + f2(t)] = £[f1(t)] + £[f2(t)] |
| 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 | |
| 112. |
For type 0 system the starting point (i.e. ω = 0) of polar plot is finite and is on positive real axis. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 113. |
For the given figure C(s)/R(s) |
| A. | K |
| B. | 0.5 K |
| C. | 2 K |
| D. | 0.25 K |
| Answer» C. 2 K | |
| 114. |
The resistance R of a liquid flow system is defined as |
| A. | |
| B. | |
| Answer» C. | |
| 115. |
The constant M loci on G(s) plane are a family of circles. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 116. |
In a second order system ωn = 10 rad/sec and ζ = 0.1, then ωd = |
| A. | 9.1 rad/sec |
| B. | 9.95 rad/sec |
| C. | 9 rad/sec |
| D. | 1 rad/sec |
| Answer» C. 9 rad/sec | |
| 117. |
The damping ratio of a pair of complex poles when expressed in terms of angle θ measured from jω axis equal to |
| A. | sin θ |
| B. | cos θ |
| C. | tan θ |
| D. | cot θ |
| Answer» B. cos Œ∏ | |
| 118. |
Consider the following statements: The positiveness of coefficients of characteristic equation is necessary as well as sufficient condition for stability of first and second order systems.The positiveness of coefficients of characteristic equation ensures negativeness of real roots but is not sufficient condition for stability of third and higher order systems. Out of above statements: |
| A. | only 2 is correct |
| B. | both are wrong |
| Answer» C. | |
| 119. |
The given figure shows a control system. The maximum value of gain for which the system is stable is |
| A. | 3 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» C. 4 | |
| 120. |
In the field controlled motor the entire damping comes from |
| A. | armature resistance |
| B. | back emf |
| C. | motor friction and load |
| D. | field resistance |
| Answer» D. field resistance | |
| 121. |
The capacitance of a gas pressure vessel is defined as |
| A. | (change in gas stored) x (change in gas pressure) |
| B. | none of the above |
| Answer» B. none of the above | |
| 122. |
In using Nyquist stability criterion it is not necessary to determine closed loop poles. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 123. |
Assertion (A): For a given system only one of the static error constants is finite and significant.Reason (R): If finite static error constant is large, the loop gain becomes smaller as ω approaches 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» D. R is correct but A is wrong | |
| 124. |
In root locus analysis the breakaway and break in points |
| A. | lie on the real axis |
| B. | either lie on the real axis or occur in complex conjugate pairs |
| C. | always occur in complex conjugate pairs |
| D. | none of the above |
| Answer» C. always occur in complex conjugate pairs | |
| 125. |
The pole zero plot of the given figure is for |
| A. | all pass function |
| B. | none of the above |
| Answer» C. | |
| 126. |
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. | A is correct but R is wrong |
| B. | R is correct but A is wrong |
| Answer» C. | |
| 127. |
The permanent magnet field system of brushless dc servo- motor is generally on |
| A. | partly on stator and partly on rotor |
| B. | either (a) or (b) |
| Answer» C. | |
| 128. |
The given figure shows a constant current source driving a parallel RC circuit. It is equivalent to |
| A. | a lag network |
| B. | a lead network |
| C. | a lag-lead network |
| D. | either (a) or (b) |
| Answer» B. a lead network | |
| 129. |
For the compensator in the given figure the maximum phase lead is |
| A. | 45° |
| B. | 60° |
| Answer» C. | |
| 130. |
Which of the following is open loop system? |
| A. | Wind screen wiper |
| B. | Aqualing |
| C. | Respiratory system of animal |
| D. | System for controlling antirocket missiles |
| Answer» B. Aqualing | |
| 131. |
In a two phase servomotor the voltages applied to the two stator windings |
| A. | are equal in magnitude and are in phase |
| B. | are unequal in magnitude but are in phase |
| C. | are equal in magnitude but have a phase difference of 90° |
| D. | are unequal in magnitude and have a phase difference of 90° |
| Answer» E. | |
| 132. |
For the system in the given figure the root locus |
| A. | is on real axis between points s = -3.6 and s = ‚àû |
| B. | is on real axis between points s = 0 and s = -3.6 |
| C. | 1 rad/sec |
| D. | 0.5 rad/sec |
| Answer» B. is on real axis between points s = 0 and s = -3.6 | |
| 133. |
Assertion (A): A. For a unity feedback system, with , the settling time of step response is constant for all values of K ‚â• 1Reason (R): The real part of the roots for all values of K ‚â• 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 | |
| 134. |
Assertion (A): Derivative control action cannot be used alone.Reason (R): Derivative control action is effective only during transient periods. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 135. |
If poles lie in first quadrant, damping ratio is |
| A. | 1 |
| B. | more than 1 |
| C. | less than 1 |
| D. | zero |
| Answer» D. zero | |
| 136. |
The slope of log magnitude asymptote changes by - 40 dB/ decade at a certain frequency and the error between asymptote and actual curve is - 6 dB. This means that |
| A. | a double pole is present |
| B. | a pair of complex conjugate poles is present |
| C. | either a double pole or a pair of complex conjugate poles is present |
| D. | either a pole or zero at that frequency is present |
| Answer» B. a pair of complex conjugate poles is present | |
| 137. |
The phase angle of is constant and equal to - 90° for all values of ω |
| A. | 1 |
| B. | |
| C. | 0% to 100% of its final value |
| D. | 10% to 90% of its final value |
| Answer» B. | |
| 138. |
A lag compensator provides attenuation in |
| A. | very low frequency range |
| B. | low frequency range |
| C. | high frequency range |
| D. | none of the above |
| Answer» D. none of the above | |
| 139. |
The phase angle curve of G(jω) H(jω) is drawn by adding the phase angles of individual factors. |
| A. | 1 |
| B. | |
| C. | voltage |
| D. | flux |
| Answer» B. | |
| 140. |
The transient response of a second order system is given by for 5% criterion the settling time is |
| A. | 0.25 sec |
| B. | 0.75 sec |
| C. | 1.25 sec |
| D. | 4 sec |
| Answer» C. 1.25 sec | |
| 141. |
In a two phasor servomotor, the direction of rotation of the rotating field depends on |
| A. | both magnitude and phase relationship of voltages applied to the two stator windings |
| B. | none of the above |
| C. | Both A and R are correct and R is correct explanation of A |
| D. | Both A and R are correct but R is not correct explanation of A |
| Answer» C. Both A and R are correct and R is correct explanation of A | |
| 142. |
For a type 0 system and unit ramp input, the steady state error is |
| A. | 1 |
| B. | 1/KV |
| Answer» C. | |
| 143. |
A proportional controller is basically |
| A. | an amplifier with adjustable gain |
| B. | an integrating amplifier |
| C. | an amplifier with infinite gain |
| D. | an amplifier with almost zero gain |
| Answer» B. an integrating amplifier | |
| 144. |
If the breakaway and break in points in the root locus are located at |
| A. | -2 and -1 |
| B. | -2.47 and -3.77 |
| C. | -4.27 and -7.73 |
| D. | none of the above |
| Answer» D. none of the above | |
| 145. |
For a type 1 system and unit step input, the steady state error is |
| A. | 1 |
| B. | |
| Answer» B. | |
| 146. |
For the system in the given figure . Then steady state error is |
| A. | |
| B. | K |
| C. | Zero |
| Answer» D. | |
| 147. |
In the given figure the number of combinations of three non touching loops is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» B. 1 | |
| 148. |
For very low frequencies, log magnitude for the given figure is |
| A. | 0 dB |
| B. | -3 dB |
| C. | 3 dB |
| D. | 10 dB |
| Answer» D. 10 dB | |
| 149. |
If Z is the number of zeros of 1 + G(s) H(s) in the right half s plane. N is the number of clockwise encircle elements of (-1 + jo) point. P is the number of poles of G(s) H(s) in right half s plane. The Nyquist stability criterion can be expressed as |
| A. | Z = N + P |
| B. | Z = P/N |
| C. | Z = N - P |
| D. | Z = PN |
| Answer» B. Z = P/N | |
| 150. |
Assertion (A): Most of actual systems are non-linear.Reason (R): Non linearity may be due to saturation, dead zone, square law etc. |
| 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 | |