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MCQOPTIONS
This section includes 977 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 851. |
The retardation of a flat faced follower when it has contact at the apex of the nose of a circular arc cam, is given by (where OQ = Distance between the centre of circular flank and centre of nose) |
| A. | ω² × OQ |
| B. | ω² × OQ sinθ |
| C. | ω² × OQ cosθ |
| D. | ω² × OQ tanθ |
| Answer» B. ≈ì√¢¬¨‚⧠‚àö√≥ OQ sin≈í‚àè | |
| 852. |
The natural frequency of free torsional vibrations of a shaft is equal to (where q = Torsional stiffness of the shaft, and I = Mass moment of inertia of the disc attached at the end of a shaft) |
| A. | 2œÄ. ‚à ö(q/I) |
| B. | 2π qI |
| C. | (1/2œÄ). ‚à ö(q/I) |
| D. | 1/2π |
| Answer» D. 1/2≈ì√Ñ | |
| 853. |
The tractive force is maximum or minimum when the angle of inclination of crank with the line of stroke (θ) is equal to$ |
| A. | 0° and 90° |
| B. | 90° and 180° |
| C. | 135° and 315° |
| D. | 270° and 360° |
| Answer» C. 135¬¨‚àû and 315¬¨‚àû | |
| 854. |
In Meyer's expansion valve, the expansion valve is driven by an eccentric having an angle of advance from |
| A. | 50°- 60° |
| B. | 60°-70° |
| C. | 70°- 80° |
| D. | 80°- 90° |
| Answer» E. | |
| 855. |
A simple spring-mass vibrating system has a natural frequency of fn. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become |
| A. | fn/2 |
| B. | 2 fn |
| C. | 4 fn |
| D. | 8 fn |
| Answer» B. 2 fn | |
| 856. |
When the axes of the first and last wheels are coaxial, then the train is known as |
| A. | Simple train of wheels |
| B. | Compound train of wheels |
| C. | Reverted gear train |
| D. | Epicyclic gear train |
| Answer» D. Epicyclic gear train | |
| 857. |
The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where l‚ÇÅ and l‚ÇÇ = Distance of two masses from the centre of gravity of the body, and kG = Radius of gyration of the body)$ |
| A. | l‚ÇÅ = kG |
| B. | l‚ÇÇ = kG |
| C. | l‚ÇÅl‚ÇÇ = kG |
| D. | l₁l₂ = kG² |
| Answer» E. | |
| 858. |
A shaft carrying two rotors at its ends will have |
| A. | No node |
| B. | One node |
| C. | Two nodes |
| D. | Three nodes |
| Answer» C. Two nodes | |
| 859. |
At the nodal point in a shaft, the amplitude for torsional vibration will be |
| A. | Minimum |
| B. | Maximum |
| C. | Zero |
| D. | Infinity |
| Answer» D. Infinity | |
| 860. |
A rotor supported at A and B carries two masses as shown in the below figure. The rotor is |
| A. | Dynamically balanced |
| B. | Statically balanced |
| C. | Statically and dynamically balanced |
| D. | Not balanced |
| Answer» D. Not balanced | |
| 861. |
The values of velocity and acceleration of piston at near dead center for a slider-crank mechanism will be |
| A. | 0, and more than co2r |
| B. | 0, and less than coV |
| C. | 0, 0 |
| D. | cor, 0 |
| Answer» B. 0, and less than coV | |
| 862. |
Which of the following is false statement in respect of differences between machine and structure? |
| A. | Machines transmit mechanical work, whereas structures transmit forces |
| B. | In machines, relative motion exists between its members, whereas same does not exist in case of structures |
| C. | Machines modify movement and work, whereas structures modify forces |
| D. | Efficiency of machines as well as structures is below 100 % |
| Answer» E. | |
| 863. |
The total number of instantaneous centers for a mechanism consisting of n links are |
| A. | n/2 |
| B. | n |
| C. | n - 1 |
| D. | n(n - 1)/2 |
| Answer» E. | |
| 864. |
The frictional torque transmitted in a conical pivot bearing, considering uniform pressure, is (where R = Radius of shaft, and α = Semi-angle of the cone)$ |
| A. | (1/2) μ W R cosecα |
| B. | (2/3) μ W R cosecα |
| C. | (3/4) μ W R cosecα |
| D. | μ W R cosecα |
| Answer» C. (3/4) ≈í¬∫ W R cosec≈í¬± | |
| 865. |
Length of arc of contact is given by |
| A. | Arc of approach - Arc of recess |
| B. | Arc of approach + Arc of recess |
| C. | Arc of approach / Arc of recess |
| D. | Arc of approach √ó Arc of recess |
| Answer» C. Arc of approach / Arc of recess | |
| 866. |
The factional torque for square thread at the mean radius r while raising load W is given by |
| A. | T = W.r tan(φ - α) |
| B. | T = W.r tan(φ + α) |
| C. | T = W.r tanα |
| D. | T = W.r tanφ |
| Answer» C. T = W.r tan≈í¬± | |
| 867. |
In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be (where ω = Angular speed of the system, ωn = Natural frequency of vibration of the system)$ |
| A. | Less than unity |
| B. | Equal to unity |
| C. | Greater than unity |
| D. | Zero |
| Answer» D. Zero | |
| 868. |
The acceleration of a particle at any instant has two components i.e. radial component and tangential component. These two components will be |
| A. | Parallel to each other |
| B. | Perpendicular to each other |
| C. | Inclined at 45° |
| D. | Opposite to each other |
| Answer» C. Inclined at 45¬¨‚àû | |
| 869. |
The Hooke's joint consists of: |
| A. | Two forks |
| B. | One fork |
| C. | Three forks |
| D. | Four forks |
| Answer» B. One fork | |
| 870. |
The Grubler's criterion for determining the degrees of freedom (n) of a mechanism having plane motion is (where l = Number of links, and j = Number of binary joints) |
| A. | n = (l -1) - j |
| B. | n = 2(l - 1) - 2j |
| C. | n = 3(l - 1) - 2j |
| D. | n = 4(l - 1) - 3j |
| Answer» D. n = 4(l - 1) - 3j | |
| 871. |
The tendency of a body to resist change from rest or motion is known as |
| A. | Mass |
| B. | Friction |
| C. | Inertia |
| D. | Resisting force |
| Answer» D. Resisting force | |
| 872. |
The primary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is |
| A. | 0° and 90° |
| B. | 0° and 180° |
| C. | 90° and 180° |
| D. | 180° and 360° |
| Answer» C. 90¬¨‚àû and 180¬¨‚àû | |
| 873. |
Transmission of power from the engine to the rear axle of an automobile is by means of |
| A. | Compound gears |
| B. | Worm and wheel method |
| C. | Hooke's joint |
| D. | Crown gear |
| Answer» D. Crown gear | |
| 874. |
The balancing of a rigid rotor can be achieved by appropriately placing balancing masses in |
| A. | A single plane |
| B. | Two planes |
| C. | Three planes |
| D. | Four planes |
| Answer» C. Three planes | |
| 875. |
When a ship travels in a sea, which of the effect is more dangerous |
| A. | Steering |
| B. | Pitching |
| C. | Rolling |
| D. | All of the above |
| Answer» C. Rolling | |
| 876. |
A system of masses rotating in different parallel planes is in dynamic balance if the |
| A. | Resultant force is equal to zero |
| B. | Resultant couple is equal to zero |
| C. | Resultant force and resultant couple are both equal to zero |
| D. | Resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero |
| Answer» D. Resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero | |
| 877. |
In the below figure, PC is the connecting rod and OC is the crank making an angle θ with the line of stroke PO and rotates with uniform angular velocity at ω rad/s. The Klien's acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral CQNO, if N coincides with O, then$ |
| A. | Acceleration and velocity of the piston P is zero |
| B. | Acceleration and velocity of the piston P is maximum |
| C. | Acceleration of the piston P is zero and its velocity is maximum |
| D. | Acceleration of the piston P is maximum and its velocity is zero |
| Answer» D. Acceleration of the piston P is maximum and its velocity is zero | |
| 878. |
If some links are connected such that motion between them can take place in more than one direction, it is called |
| A. | Incompletely constrained motion |
| B. | Partially constrained motion |
| C. | Completely constrained motion |
| D. | Successfully constrained motion |
| Answer» B. Partially constrained motion | |
| 879. |
Flexible coupling is used because |
| A. | It is easy to disassemble |
| B. | It is easy to engage and disengage |
| C. | It transmits shocks gradually |
| D. | It prevents shock transmission and eliminates stress reversals |
| Answer» E. | |
| 880. |
The balancing weights are introduced in planes parallel to the plane of rotation of the disturbing mass. To obtain complete dynamic balance, the minimum number of balancing weights to be introduced in different planes is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 881. |
The velocity of a body moving with simple harmonic motion is __________ at the mean position. |
| A. | Zero |
| B. | Minimum |
| C. | Maximum |
| D. | None of these |
| Answer» D. None of these | |
| 882. |
The instantaneous centers which vary with the configuration of mechanism are called |
| A. | Permanent instantaneous centers |
| B. | Fixed instantaneous centers |
| C. | Neither fixed nor permanent instantaneous centers |
| D. | None of the above |
| Answer» D. None of the above | |
| 883. |
Two heavy rotating masses are connected by shafts of lengths l‚ÇÅ, l‚ÇÇ and l‚ÇÉ and the corresponding diameters are d‚ÇÅ, d‚ÇÇ and d‚ÇÉ. This system is reduced to a torsionally equivalent system having uniform diameter d = d‚ÇÅ of the shaft. The equivalent length of the shaft is$ |
| A. | (l‚ÇÅ + l‚ÇÇ + l‚ÇÉ)/3 |
| B. | l = l₁ + l₂.(d₁/d₂)³ + l₂.(d₁/d₃)³ |
| C. | l = l‚ÇÅ + l‚ÇÇ.(d‚ÇÅ/d‚ÇÇ)‚Å¥ + l‚ÇÉ.(d‚ÇÅ/d‚ÇÉ)‚Å¥ |
| D. | l‚ÇÅ + l‚ÇÇ + l‚ÇÉ |
| Answer» D. l‚Äö√á√Ö + l‚Äö√á√á + l‚Äö√á√â | |
| 884. |
The periodic time of a compound pendulum is __________ when the distance between the point of suspension and the center of gravity is equal to the radius of gyration of the body about its center of gravity. |
| A. | Zero |
| B. | Minimum |
| C. | Maximum |
| D. | None of these |
| Answer» C. Maximum | |
| 885. |
Sense of tangential acceleration of a link |
| A. | Is same as that of velocity |
| B. | Is opposite to that of velocity |
| C. | Could be either same or opposite to velocity |
| D. | Is perpendicular to that of velocity |
| Answer» D. Is perpendicular to that of velocity | |
| 886. |
The power of a Porter governor is equal to |
| A. | [c²/(1 + 2c)] (m + M) g.h |
| B. | [2c²/(1 + 2c)] (m + M) g.h |
| C. | [3c²/(1 + 2c)] (m + M) g.h |
| D. | [4c²/(1 + 2c)] (m + M) g.h |
| Answer» E. | |
| 887. |
A slider moves at a velocity v on a link revolving at ω rad/s. The coriolis component of acceleration is$ |
| A. | ωv |
| B. | 2ωv |
| C. | ω²v |
| D. | 2ωv² |
| Answer» C. ≈ì√¢¬¨‚â§v | |
| 888. |
Maximum fluctuation of energy in a flywheel is equal to [where I = Mass moment of inertia of the flywheel, E = Maximum fluctuation of energy, CS = Coefficient of fluctuation of speed, and ω = Mean angular speed = (ω₁ + ω₂)/2]$ |
| A. | I.ω.(ω₁ - ω₂) |
| B. | I.ω².CS |
| C. | 2.E.CS |
| D. | All of these |
| Answer» E. | |
| 889. |
Klein's construction is useful to determine |
| A. | Velocity of various parts |
| B. | Acceleration of various parts |
| C. | Displacement of various parts |
| D. | Angular acceleration of various parts |
| Answer» C. Displacement of various parts | |
| 890. |
In under damped vibrating system, if x‚ÇÅ and x‚ÇÇ are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to$ |
| A. | x‚ÇÅ/x‚ÇÇ |
| B. | log(x‚ÇÅ/x‚ÇÇ) |
| C. | loge(x‚ÇÅ/x‚ÇÇ) |
| D. | log(x‚ÇÅ.x‚ÇÇ) |
| Answer» C. loge(x‚Äö√á√Ö/x‚Äö√á√á) | |
| 891. |
In an ideal machine, the output as compared to input is |
| A. | Less |
| B. | More |
| C. | Equal |
| D. | May be less or more depending on efficiency |
| Answer» D. May be less or more depending on efficiency | |
| 892. |
An engine operates between temperatures of 900°Kandr2 and another engine between T2 and 400°K For both to do equal work, value of T2 will be$ |
| A. | 650°K |
| B. | 600°K |
| C. | 625°K |
| D. | 700°K |
| Answer» B. 600¬¨‚àûK | |
| 893. |
Whirling speed of the shaft is the speed at which |
| A. | Shaft tends to vibrate in longitudinal direction |
| B. | Torsional vibrations occur |
| C. | Shaft tends to vibrate vigorously in transverse direction |
| D. | Combination of transverse and longitudinal vibration occurs |
| Answer» D. Combination of transverse and longitudinal vibration occurs | |
| 894. |
The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve. |
| A. | Greater than |
| B. | Less than |
| C. | Equal to |
| D. | None of these |
| Answer» B. Less than | |
| 895. |
When the nature of contact between the elements of a pair is such that one element can turn about the other by screw threads, the pair is known as a |
| A. | Screw pair |
| B. | Spherical pair |
| C. | Turning pair |
| D. | Sliding pair |
| Answer» B. Spherical pair | |
| 896. |
The primary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, θ = Angle of inclination of crank with the line of stroke, and n = Ratio of the length of connecting rod to radius of crank)$ |
| A. | m.ω².r sinθ |
| B. | m.ω².r cosθ |
| C. | m.ω².r (sin 2θ/n) |
| D. | m.ω².r (cos 2θ/n) |
| Answer» C. m.≈ì√¢¬¨‚â§.r (sin 2≈í‚àè/n) | |
| 897. |
The lower pairs are _________ pairs. |
| A. | Self-closed |
| B. | Force-closed |
| C. | Friction closed |
| D. | None of these |
| Answer» B. Force-closed | |
| 898. |
A torsional system with discs of moment of inertia I‚ÇÅ and I‚ÇÇ as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to$ |
| A. | G.I‚ÇÇ |
| B. | G².I₂ |
| C. | I‚ÇÇ/G |
| D. | I₂/G² |
| Answer» C. I‚Äö√á√á/G | |
| 899. |
For a twin cylinder V-engine, the crank positions for primary reverse cranks and secondary direct cranks are shown in the below figure. The engine is a |
| A. | 30° V-engine |
| B. | 60° V-engine |
| C. | 120° V-engine |
| D. | 150° V-engine |
| Answer» B. 60¬¨‚àû V-engine | |
| 900. |
The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)$ |
| A. | sin (θ + φ) + 1/ cos (θ - φ) + 1 |
| B. | cos (θ - φ) + 1/ sin (θ + φ) + 1 |
| C. | cos (θ + φ) + 1/ cos (θ - φ) + 1 |
| D. | cos (θ - φ) + 1/ cos (θ + φ) + 1 |
| Answer» D. cos (≈í‚àè - ≈ì√ú) + 1/ cos (≈í‚àè + ≈ì√ú) + 1 | |