Theory of machine Mcq

Theory of machine Mcq 

01. In a reciprocating steam engine,

which of the following forms a kinematic link?

A. Crankshaft and flywheel

Exp. Each resistant body in a machine which moves relative to another resistant body is called Kinematic link or element.

02. The maximum velocity of a particle moving with simple harmonic motion is

A. ωr

Exp. oscillatory motion under a retarding force proportional to the amount of displacement from an equilibrium position.

03. When the tip of a tooth undercuts the root on its mating gear, it is known as

A. interference.

04. Under logarithmic decrement, the amplitude of successive vibrations is

A .in geometric progression

Exp. the maximum extent of a vibration or oscillation, measured from the position of equilibrium.

05. In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is Constant, then

A. crossed belt drive is recommended

06. The tractive force is maximum or minimum when the angle of inclination of crank with the line of stroke (θ) is equal to

A .90° and 180°

Exp. Traction, or tractive force, is the force used to generate motion between a body and a tangential surface, using dry friction, though the use of shear force of the surface is also commonly used.

07. A point on a connecting link (excluding end points) of a double slider crank mechanism traces a

A. Elliptical path

08. According to Kennedy's theorem, if three bodies move relatively to each other, their instantaneous centres will lie on a

A. straight line

09. The periodic time is given by (where ω = Angular velocity of the particle in rad/s)

A .2π/ω

10. When two links are connected by a pin joint, their instantaneous centre lies

D.at the pin joint

11. The brake commonly used in railway trains is

A. shoe brake

12. The acceleration of the particle moving with simple harmonic motion is zero at the

A. mean position.

Exp. SHM is oscillatory motion under a retarding force proportional to the amount of displacement from an equilibrium position.

13. A system of masses rotating in different parallel planes is in dynamic balance if the

A. resultant force and resultant couple are both equal to zero

14. The radial distance from the top of a tooth to the bottom of a tooth in a meshing gear, is called

A. clearance

Exp. Gears are toothed wheels which are used to transmit force to other gears or toothed parts by meshing with minimal slip. When two gears are meshed together, the smaller gear is called a pinion. The gear transmitting force is referred to as a drive gear, and the receiving gear is called the driven gear.

15. Bifilar suspension method is used to find the

A. moment of inertia of the body

16. The motion between a pair when limited to a definite direction, irrespective of the direction of force applied, is known as

A. completely constrained motion

Exp. Completely constrained motion is a type of constrained motion in which relative motion between the links of a kinematic pair occurs in a definite direction by itself, irrespective of the external forces applied.

17. The motion of a shaft in a circular hole is an example of

A. incompletely constrained motion

18. A spring-controlled governor is said to be unstable when the controlling force

A. decreases as the radius of rotation increases

19. 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

Exp.

A screw pair requires cut threads in two links, so that there is a turning as well as sliding motion between them. This joint has one degree of freedom. A cylindrical joint requires that a line in the moving body remain co-linear with a line in the fixed body.

20. In a locomotive, the resultant unbalanced force due to the two cylinders along the line of stroke, is known as

A. tractive force

Exp. Traction, or tractive force, is the force used to generate motion between a body and a tangential surface, using dry friction, though the use of shear force of the surface is also commonly used.

21. Which of the following is an example of sliding pair?

A. Piston and cylinder of a reciprocating steam engine.

Exp. Sliding Pair: As the name suggests, a sliding pair is a kinematic pair in which each element has sliding contact with respect to the other element.

22. The coriolis component of acceleration exists whenever a point moves along a path that has

A. rotational motion

Exp. Rotational motion is motion which follows a curved path.

23. The stress induced in a body will be shear stress, when it is subjected to

C.torsional vibrations

Exp. Torsional vibration is angular vibration of an object—commonly a shaft along its axis of rotation.

24. When a body is subjected to longitudinal vibrations, the stress induced in a body will be

A. tensile or compressive stress.

25. The maximum displacement of a body, from its mean position is called.

A. amplitude

Exp. Amplitude means the maximum extent of a vibration or oscillation, measured from the position of equilibrium.

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