Theory of Machines - Mechanical Engineering MCQ

A machine is coupled to a two stroke engine which produces a torque of [800 + 180 sin 3θ] [N m], where θ is the crank angle. The maximum fluctuation of energy, if resisting torque is constant is ___________ Nm

(Important - Enter only the numerical value in the answer)

When bar AB is in the position shown, end B is sliding to the right with a velocity of 0.8 m/ sec. Velocity of A in this position is –––––– m/sec.

(Important - Enter only the numerical value in the answer)

A rod AB experiences different velocities at point A and B. Figure shows the instant when the rod is horizontal while moving in the vertical plane. At this instant the location of instantaneous centre for velocities and the angular velocity of the rod respectively are.

A riveting machine is driven by a motor of 3 KW. It takes 1 sec and 12 KN-m of energy to complete one riveting operation. The moment of Inertia of fly wheel is 55 (kg m²). The speed of the fly wheel immediately after riveting, if it is 360 rpm before riveting is ––––––– rpm.

(Important - Enter only the numerical value in the answer)

In a certain slider crank mechanism length of connecting rod is very large as compared to crank length. If x is the displacement of piston at the moment when the crank has turned through an angle of 30° from Inner dead centre, for crank length of 300 mm, value of x = –––– mm.

(Important - Enter only the numerical value in the answer)

In a slider crank mechanism, the maximum acceleration of slider is obtained when the crank is

In the case of fly wheel, the maximum fluctuation of energy is.

In the diagram given, the magnitude of absolute angular velocity of link 2 is (10 rad/sec) while that of link 3 is (6 rad/sec). Angular velocity of link 3 relative to 2 is –––––––– rad/sec. [Magnitude only]

(Important - Enter only the numerical value in the answer)

In an elliptical trammel, the length of the link connecting the two sliders is 100 mm. The tracing pen is placed on 150 mm extension of this link. The major and minor axes of the ellipse traced by the mechanism would be

Degrees of freedom of following mechanism is 

(Important - Enter only the numerical value in the answer)

In a bar mechanism with all four links of different lengths, doublecrank behavior was observed when one of the links was fixed. After modification if the fixed links is set free and the link adjacent to it is fixed. The mechanism will behave as:-

The given figure shows a

At an instant a circular body P is observed [refer figure]. Velocities at point A and B are horizontal and opposite in direction. The instantaneous centre of rotation of the body will lie at

No. of Ternary links and degree of freedom of the mechanism respectively are

In the mechanism shown, the degree of freedom using Gruebler’s criterion is ________ rad/s

(Important - Enter only the numerical value in the answer)

In the given figure the mechanism has single degree of freedom. At an instant when the link 3 makes an angle of 600 with horizontal, the downward velocity of slider link 2 is 1 m/sec. if the length of link 3 is 1 m. The angular velocity of link 3 at this instant will be_______ (rad/sec)

(Important - Enter only the numerical value in the answer)

To use slider-crank chain mechanism in shaper to have a quick return stroke, which of the links is to be fixed?

Figure shows a wheel rotating about centre O. Two points A and B located on the diameter O₁ O₂ of the wheel have speeds of 90 m/sec and 105 m/sec respectively. Distance b/w points A and B is 650 mm. diameter of the wheel is _____ mm
[BO₂ is 50 mm]

(Important - Enter only the numerical value in the answer)

In the figure given the link 2 rotates at an angular velocity of 2 rad/sec. what is the magnitude of corioli’s, acceleration experienced by link 4 at given instance

For a mechanism consisting of 14 links, to have one degree of freedom with all revolute pairs. The no. of revolute pairs is ________

(Important - Enter only the numerical value in the answer)

For the mechanism shown Angular velocity of link AO₂ at this instant is _____ rad/sec 

[Use instantaneous centre Method]

(Important - Enter only the numerical value in the answer)

Two disc 1 and 2 are arranged as shown in the figure are pined at centres O₁ and O₂ and have radii r₁ =4m and r₂ =8m respectively. If disc 1 is rotating at 600rpm. Difference between the velocities at point A and B is ________ m/sec

(Important - Enter only the numerical value in the answer)