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This section includes 63 Mcqs, each offering curated multiple-choice questions to sharpen your Geotechnical Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
In stability computation, the curve representing the real surface of sliding is usually replaced by ___________ |
A. | Arc of circle and Logarithmic failure |
B. | Cycloid |
C. | None of the mentioned |
D. | All of the mentioned |
Answer» B. Cycloid | |
2. |
The rupture mass sliding down a surface in a definite pattern resembles __________ |
A. | Curve |
B. | Cycloid |
C. | Ellipse |
D. | Circle |
Answer» C. Ellipse | |
3. |
According to Bennet, non-circular slip surface may arise in ___________ |
A. | Non homogeneous dam |
B. | Embankment dams |
C. | Homogeneous dam |
D. | Soil deposit with a specific plane of weakness |
Answer» D. Soil deposit with a specific plane of weakness | |
4. |
Planar surface commonly occur in __________ |
A. | Embankment with specific plane of weakness |
B. | All embankments |
C. | Soil deposit |
D. | Foundation of infinite depth |
Answer» B. All embankments | |
5. |
The depth factor Df for toe failure is ___________ |
A. | Df > 1 |
B. | Df < 1 |
C. | Df = 1 |
D. | Df = 0 |
Answer» D. Df = 0 | |
6. |
The ratio of total depth to depth H is called _________ |
A. | Depth factor |
B. | Slope depth |
C. | Depth failure |
D. | Base failure |
Answer» B. Slope depth | |
7. |
The types of slip surface or failure surfaces are ____________ |
A. | 4 |
B. | 2 |
C. | 3 |
D. | 5 |
Answer» D. 5 | |
8. |
If the failure occurs along a surface of sliding that intersect the slope at its toe, the slide is known as ___________ |
A. | Base failure |
B. | Slope failure |
C. | Face failure |
D. | All of the mentioned |
Answer» C. Face failure | |
9. |
A basic type of failure at a finite slope may occur due to ___________ |
A. | Slope failure and Base failure |
B. | Toe failure |
C. | None of the mentioned |
D. | All of the mentioned |
Answer» B. Toe failure | |
10. |
For \(G\left( s \right)H\left( s \right) = \frac{1}{{s + 2}}\) , the system is: |
A. | Stable, has one zero |
B. | stable, has no zeros |
C. | Unstable has no zeros |
D. | Unstable, has one zero |
Answer» C. Unstable has no zeros | |
11. |
A system described by the transfer function \(H\left( s \right) = \frac{1}{{{s^3} + a{s^2} + ks + 3}}\) is stable. The constraints on a and k are |
A. | a > 0, a k < 3 |
B. | a > 0, a k > 3 |
C. | a > 0, a k > 0 |
D. | a > 0, a k < 0 |
Answer» C. a > 0, a k > 0 | |
12. |
A unity feedback control system has the open loop transfer function G(s). For the system to be stable find the range of K.\(G\left( s \right) = \frac{{K\left( {s + 13} \right)}}{{s\left( {s + 7} \right)\left( {s + 3} \right)}}\) |
A. | [0, 70] |
B. | [0, 80] |
C. | [0, 90] |
D. | [0, 75] |
Answer» B. [0, 80] | |
13. |
A feedback system with characteristic equation s4 + 20Ks3 + 5s2 + 10s + 15 = 0 is: |
A. | Stable for all values of K |
B. | Stable only for K ≥ 0 |
C. | Stable for ∞ > K > 70 |
D. | Unstable for all values of K |
Answer» E. | |
14. |
Check the system with characteristic equation F(s) = s4 + 3s3 + 2s2 + s + 1 for stability. |
A. | quasi-stable |
B. | Oscillatory |
C. | Unstable |
D. | Stable |
Answer» D. Stable | |
15. |
Find the number of poles in the left half plane (LHP), the right half plane (RJP) and on the jω-axis for the feedback control system as shown. Is the system stable? |
A. | 1 LHP poles; 3 RHP poles; 0 jω poles; system is stable |
B. | 2 LHP poles; 2 RHP poles; 0 jω poles; system is unstable |
C. | 2 LHP ploes; 2 RHP poles; 0 jω poles; system is stable |
D. | 1 LHP poles; 3 RHP poles; 0 jω poles; system is unstable |
Answer» C. 2 LHP ploes; 2 RHP poles; 0 jω poles; system is stable | |
16. |
A system with characteristic equation s4 + 2 s3 + 11 s2 + 18s + 18 = 0 will have closed loop poles such that |
A. | All poles lie in the left half of the s-plane |
B. | All poles lie in the right half of the s-plane |
C. | Two poles lie symmetrically on the imaginary axis of the s-plane |
D. | No pole lies on the imaginary axis of the s-plane |
Answer» D. No pole lies on the imaginary axis of the s-plane | |
17. |
A closed-loop system is shown in the figure. The system parameter α is not known. The condition for asymptotic stability of the closed loop system is |
A. | α < -0.5 |
B. | -0.5 < α < 0.5 |
C. | 0 < α < 0.5 |
D. | α > 0.5 |
Answer» E. | |
18. |
If any root of the characteristic equation has a positive real part or if there is a repeated root on the jω-axis, then the system is |
A. | Limitedly stable |
B. | Conditionally stable |
C. | Stable |
D. | Unstable |
Answer» E. | |
19. |
Consider a negative unity feedback system with the forward path transfer function \(\frac{{{s^2} + s + 1}}{{{s^3} + 2{s^2} + 2s + K}}\), where K is a positive real number. The value of K for which the system will have some of its poles on the imaginary axis is ________ |
A. | 9 |
B. | 8 |
C. | 7 |
D. | 6 |
Answer» C. 7 | |
20. |
Match the inferences X, Y, and Z, about a system, to the corresponding properties of the elements of first column in Routh’s Table of the system characteristic equation.X: The system is stable …Y: The system is unstable …Z: The test breaks down …P: … when all elements are positiveQ: … when any one element is zeroR: … when there is a change in sign of coefficients |
A. | X→P, Y→Q, Z→R |
B. | X→Q, Y→P, Z→R |
C. | X→R, Y→Q, Z→P |
D. | X→P, Y→R, Z→Q |
Answer» E. | |
21. |
A system's open-loop transfer function is given by \(G\left( s \right) = \frac{K}{{s\left( {s + 2} \right)\left( {s + 4} \right)}}\). If the system is having a unity negative feedback, which of the following is true for such a system to be stable? |
A. | K > 0 |
B. | 0 < K < 24 |
C. | K < 24 |
D. | None of the above |
Answer» C. K < 24 | |
22. |
For the equation s3 – 4s2 + s + 6 = 0, the number of roots in the left half of s-plane will be: |
A. | Zero |
B. | One |
C. | Two |
D. | Three |
Answer» C. Two | |
23. |
A closed-loop control system has a characteristic equation given by s3 + 2.4s2 + 1.8s + 0.5 = 0. Find out the value of a, b, c, and d using the Routh Hurwitz criterion.s311.8s22.40.5s1acs0bd |
A. | a = 2, b = 0.5, c = 0, d = 1.3 |
B. | a = 0, b = 0, c = 0, d = 0 |
C. | a = 1.59, b = 0.5, c = 0, d = 0 |
D. | a = 4, b = 0, c = 9, d = 0.7 |
Answer» D. a = 4, b = 0, c = 9, d = 0.7 | |
24. |
In the formation of Routh-Hurwitz array for a polynomial, all the elements of a row have zero values. This premature termination of the array indicates the presence of1. a pair of real roots with opposite sign2. complex conjugate roots on the imaginary axis3. a pair of complex conjugate roots with opposite real partsWhich of the above statements are correct? |
A. | Only 2 |
B. | 2 and 3 |
C. | Only 3 |
D. | 1, 2 and 3 |
Answer» E. | |
25. |
For the feedback system given below, the transfer function \(G\left( s \right) = \frac{1}{{{{\left( {s + 1} \right)}^2}}}.\) The system CAN NOT be stabilized with |
A. | \(C\left( s \right) = 1 + \frac{3}{s}\) |
B. | \(C\left( s \right) = 3 + \frac{7}{s}\) |
C. | \(C\left( s \right) = 3 + \frac{9}{s}\) |
D. | \(C\left( s \right) = \frac{1}{s}\) |
Answer» D. \(C\left( s \right) = \frac{1}{s}\) | |
26. |
Consider the polynomial equation below:s4 + 2s3 + 3s2 + 4s + 5 = 0The number of roots with positive real part are: |
A. | 2 |
B. | 3 |
C. | 1 |
D. | 0 |
Answer» B. 3 | |
27. |
In the formation of Routh-Hurwitz array for a polynomial, all the elements of a row have zero values. This premature termination of the array indicates the presence of |
A. | only one root at the origin |
B. | imaginary roots |
C. | only positive real roots |
D. | only negative real roots |
Answer» C. only positive real roots | |
28. |
Forward path transfer function of a unity feedback system is \(G\left( s \right) = \frac{K}{{\left( {s + 5} \right)\left( {s + 10} \right)\left( {s + 15} \right)}}\)Select the appropriate value of K for the system to be oscillatory. |
A. | 4000 |
B. | 5250 |
C. | 2400 |
D. | 7500 |
Answer» E. | |
29. |
a0 sn + a1 sn-1 + a2sn-2 + ...........+ an-1 s1 + an The necessary condition for system stability for the above characteristic equation is |
A. | All the coefficients of the characteristic equation should be zero. |
B. | All the coefficient of the characteristic equation should be unity. |
C. | All the coefficients of the characteristic equation should be positive and real. |
D. | All the coefficients of the characteristic equation should be negative and imaginary. |
Answer» D. All the coefficients of the characteristic equation should be negative and imaginary. | |
30. |
Find the range of K for the system shown in the figure to be stable.Where \(G\left( s \right) = \frac{K}{{{s^2} + 2s + 4}}\) and \(H\left( s \right) = \frac{1}{{{s^2} + 3s + 5}}\) |
A. | -5 < K < -2 |
B. | -1 < K < 1 |
C. | -2 < K < 0 |
D. | All of the above |
Answer» E. | |
31. |
Consider the following statements with respect to Routh-Hurwitz criterion:1. It can be used to determine relative stability2. It is valid only for real coefficients of the characteristic equation.3. It is applicable only for non-linear systems.4. It does not provide the exact location of closed-loop poles in left or right-half of s-planeWhich of the above statements are correct? |
A. | 1, 2 and 3 only |
B. | 3 and 4 only |
C. | 1, 2 and 4 only |
D. | 1, 2, 3 and 4 |
Answer» D. 1, 2, 3 and 4 | |
32. |
A discrete time system is stable if all the roots of the characteristic equation lie |
A. | Outside the circle of unit radius |
B. | Within the circle of unit radius |
C. | Outside of circle of radius equal to 3 units |
D. | On the circle of infinite radius |
Answer» C. Outside of circle of radius equal to 3 units | |
33. |
A unit feedback system has the open loop transfer function \(G(s) = \frac {10^4}{s(s+10)^2}\). The closed loop system is |
A. | stable |
B. | marginally stable |
C. | unstable |
D. | stable at an angular frequency of 10 rad / s |
Answer» D. stable at an angular frequency of 10 rad / s | |
34. |
Consider the stability of the system shown in the figure when analysed with a positive real value of gain K in1. open-loop configuration2. closed-loop configurationWhich of the following statements is correct? |
A. | Both 1 and 2 are stable |
B. | 1 is stable and 2 is unstable |
C. | 1 is unstable and 2 is stable |
D. | Both 1 and 2 are unstable |
Answer» D. Both 1 and 2 are unstable | |
35. |
If the system is stable by producing an output signal with constant amplitude and constant frequency of oscillations for bounded Input, then it is known as _______. |
A. | Constant stable system |
B. | Absolutely stable system |
C. | Conditionally stable system |
D. | Marginally stable system |
Answer» E. | |
36. |
How many roots of the following equation lie in the right-half of s-plane?2s4 + s3 + 2s2 + 5s + 10 = 0 |
A. | 1 |
B. | 2 |
C. | 3 |
D. | 4 |
Answer» C. 3 | |
37. |
A closed loop system has the characteristic equation given by s3 + Ks2 + (K + 2)s + 3 = 0. For this system to be stable, which one of the following conditions should be satisfied? |
A. | 0 < K < 0.5 |
B. | 0.5 < K < 1 |
C. | 0 < K < 1 |
D. | K > 1 |
Answer» E. | |
38. |
Find the number of poles in the right-half plane (RHP) for the system as shown. Is the system stable? |
A. | 2 RHP poles; System is unstable |
B. | 2 RHP poles; System is stable |
C. | 3 RHP poles; System is unstable |
D. | 3 RHP poles; System is stable |
Answer» B. 2 RHP poles; System is stable | |
39. |
Find the locations of any two roots of the characteristic equation F(s) = s4 + 2s3 + 11s2 + 18s + 18 = 0 |
A. | ± J9 |
B. | ± j3 |
C. | 0, 9 |
D. | +j9, -j2 |
Answer» C. 0, 9 | |
40. |
For a stable system, poles of the transfer function |
A. | should lie entirely in the right half of the s-plane |
B. | should lie on the Y-axis |
C. | should lie entirely in the left half of the s-plane |
D. | should lie at the origin |
Answer» D. should lie at the origin | |
41. |
For making an unstable system stable |
A. | Gain of the system should be increased. |
B. | Gain of the system should be decreased. |
C. | The number of zeros to the loop transfer function should be increased |
D. | The number of poles to the loop transfer function should be increased |
Answer» B. Gain of the system should be decreased. | |
42. |
Consider a unity feedback configuration with a plant and a PID controller as shown in the figure. \(G(s) = \frac{1}{(s+1)(s+3)}\) and \(C(s) = K \frac{(s+3-j)(s+3+j)}{s}\)with K being scaler. the closed loop is |
A. | only stable for K > 0 |
B. | only stable for K between -1 and +1 |
C. | only stable for K < 0 |
D. | stable for all values of K |
Answer» B. only stable for K between -1 and +1 | |
43. |
None of the poles of a linear control system lies in the right-half of s-plane. For a bounded input, the output of this system |
A. | is always bounded |
B. | could be unbounded |
C. | always tends to zero |
D. | None of the above |
Answer» C. always tends to zero | |
44. |
If the characteristic equation of a feedback control system is given by s4 + 20s3 + 15s2 + 2s + k = 0 Then the range of values of K for the system to be stable will be |
A. | 1 < K < 2.49 |
B. | 0 < K < 1.49 |
C. | 1 < K < 4.49 |
D. | 0 < K < 3.49 |
Answer» C. 1 < K < 4.49 | |
45. |
In Routh-Hurwitz Criterion, if all the elements in one row are zero, then there can be |
A. | pairs of equal roots with opposite sign |
B. | pairs of conjugate roots on imaginary axis |
C. | conjugate roots forming a quadrature in the s-plane |
D. | all of the above |
Answer» E. | |
46. |
If all the roots of the characteristic equation have negative real parts, the system is |
A. | Stable |
B. | Unstable |
C. | Marginally stable |
D. | Conditionally stable |
Answer» B. Unstable | |
47. |
A plant transfer function is given as,\({\rm{G}}\left( {\rm{s}} \right) = \left( {{{\rm{K}}_{\rm{p}}} + \frac{{{{\rm{K}}_{\rm{I}}}}}{{\rm{s}}}} \right)\frac{1}{{{\rm{s}}\left( {{\rm{s}} + 2} \right)}}\)When the plant operates in a unity feedback configuration the condition for the stability of the closed-loop system is |
A. | \({{\rm{K}}_{\rm{P}}} > \frac{{{{\rm{K}}_{\rm{I}}}}}{2} > 0\) |
B. | \(2{{\rm{K}}_{\rm{I}}}{\rm{\;}} > {\rm{\;}}{{\rm{K}}_{\rm{P}}}{\rm{\;}} > {\rm{\;}}0\) |
C. | \(2{{\rm{K}}_{\rm{I}}}{\rm{\;}} < {\rm{\;}}{{\rm{K}}_{\rm{P}}}\) |
D. | \(2{{\rm{K}}_{\rm{I}}}{\rm{\;}} > {\rm{\;}}{{\rm{K}}_{\rm{P}}}\) |
Answer» B. \(2{{\rm{K}}_{\rm{I}}}{\rm{\;}} > {\rm{\;}}{{\rm{K}}_{\rm{P}}}{\rm{\;}} > {\rm{\;}}0\) | |
48. |
Determine the range of K for stability of unity feedback system whose open loop transfer function is G(s)=K/s(s+1)(s+2) |
A. | 10 |
B. | 15 |
C. | 6 |
D. | 0 |
Answer» E. | |
49. |
If repeated poles of a system lie on the imaginary axis, the system will be |
A. | Stable |
B. | Conditionally stable |
C. | Marginally stable |
D. | Unstable |
Answer» E. | |
50. |
Consider a closed loop system with transfer function \(\frac{{C\left( s \right)}}{{R\left( s \right)}} = \frac{{{s^2} + 2s + 8}}{{{s^3} + 2{s^2} + 6s + 10}}\).Find the number of poles in right half of s plane and in he left half of s plane. |
A. | 3, 1 |
B. | 0, 3 |
C. | 3, 2 |
D. | 5, 4 |
Answer» C. 3, 2 | |