Home
Current Affairs January 2024

What is the correct answer?

4

Lower pairs are those which have

A. Point or line contact between the two elements when in motion

B. Surface contact between the two elements when in motion

C. Elements of pairs not held together mechanically

D. Two elements that permit relative motion

Correct Answer :

B. Surface contact between the two elements when in motion


Related Questions

What is the correct answer?

4

The coriolis component of acceleration is taken into account for

A. Slider crank mechanism

B. Four bar chain mechanism

C. Quick return motion mechanism

D. All of these

What is the correct answer?

4

The ratio of height of Porter governor (when length of arms and links are equal) to the height of Watt's governor is (where m = Mass of the ball, and M = Mass on the sleeve)

A. m/(m + M)

B. M/(m + M)

C. (m + M)/m

D. (m + M)/M

What is the correct answer?

4

In a hydrodynamic journal bearing, there is

A. A very thin film of lubricant between the journal and the bearing such that there is contact between the journal and the bearing

B. A thick film of lubricant between the journal and the bearing

C. No lubricant between the journal and the bearing

D. A forced lubricant between the journal and the bearing

What is the correct answer?

4

In a pantograph, all the pairs are

A. Turning pairs

B. Sliding pairs

C. Spherical pairs

D. Self-closed pairs

What is the correct answer?

4

When the particles of a body moves perpendicular to its axis, then the body is said to have

A. Longitudinal vibration

B. Transverse vibration

C. Torsional vibration

D. None of these

What is the correct answer?

4

The gears are termed as medium velocity gears, if their peripheral velocity is

A. 1-3 m/s

B. 3-15 m/s

C. 15-30 m/s

D. 30-50 m/s

What is the correct answer?

4

The primary unbalanced force is maximum _________ in one revolution of the crank.

A. Twice

B. Four times

C. Eight times

D. Sixteen times

What is the correct answer?

4

Critical damping is a function of

A. Mass and stiffness

B. Mass and damping coefficient

C. Mass and natural frequency

D. Damping coefficient and natural frequency

What is the correct answer?

4

The component of the acceleration, parallel to the velocity of the particle, at the given instant is called

A. Radial component

B. Tangential component

C. Coriolis component

D. None of these

What is the correct answer?

4

The flank of the tooth is the surface of the tooth __________ the pitch surface.

A. Above

B. Below

C. At

D. None of these

What is the correct answer?

4

In order to give a complete secondary balance of a multi-cylinder inline engine,

A. The algebraic sum of the secondary forces must be equal to zero

B. The algebraic sum of the couples about any point in the plane of the secondary forces must be equal to zero

C. Both (A) and (B)

D. None of these

What is the correct answer?

4

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

What is the correct answer?

4

The ratio of the number of teeth to the pitch circle diameter in millimetres, is called

A. Circular pitch

B. Diametral pitch

C. Module

D. None of these

What is the correct answer?

4

A mass of 1 kg is attached to the end of a spring with a stiffness of 0.7 N/mm. The critical damping coefficient of this system is

A. 1.4 N-s/m

B. 18.52 N-s/m

C. 52.92 N-s/m

D. 529.2 N-s/m

What is the correct answer?

4

A rigid body possesses ________degrees of freedom

A. One

B. Two

C. Four

D. Six

What is the correct answer?

4

The D-slide valve is also known as

A. Inside admission valve

B. Outside admission valve

C. Piston slide valve

D. None of these

What is the correct answer?

4

The axis of precession is __________ to the plane in which the axis of spin is going to rotate.

A. Parallel

B. Perpendicular

C. Both A and B

D. None of these

What is the correct answer?

4

Which is the false statement about the properties of instantaneous centre?

A. At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered

B. The two rigid links have no linear velocities relative to each other at the instantaneous centre

C. The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link

D. The double centre can be denoted either by O2 or O12, but proper selection should be made

What is the correct answer?

4

If the radius of gyration of a compound pendulum about an axis through e.g. is more, then its frequency of oscillation will be

A. Less

B. More

C. Same

D. Data are insufficient to determine same

What is the correct answer?

4

In a simple train of wheels, the velocity ratio __________ the intermediate wheels.

A. Depends upon

B. Is independent of

C. Either A or B

D. None of these

What is the correct answer?

4

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

A. Straight line

B. Parabolic curve

C. Triangle

D. Rectangle

What is the correct answer?

4

Cylindrical cams can be classified as

A. Circular

B. Tangent

C. Reciprocating

D. None of the above

What is the correct answer?

4

Sensitiveness of the governor is defined as the ratio of the

A. Mean speed to the maximum equilibrium speed

B. Mean speed to the minimum equilibrium speed

C. Difference of the maximum and minimum equilibrium speeds to the mean speed

D. Sum of the maximum and minimum equilibrium speeds to the mean speed

What is the correct answer?

4

The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body, and δ = Static deflection of the body)

A. 1/2π × √(s/m)

B. 1/2π × √(g/δ)

C. 0.4985/√δ

D. Any one of these

What is the correct answer?

4

A rotary internal combustion engine has __________ cylinders.

A. Four

B. Five

C. Six

D. Seven

What is the correct answer?

4

The number of links and instantaneous centers in a reciprocating engine mechanism are

A. 4, 4

B. 4, 5

C. 5, 4

D. 4, 6

What is the correct answer?

4

The minimum number of teeth on the pinion which will mesh with any gear without interference for 20° full depth involute teeth will be

A. 12

B. 14

C. 18

D. 24

What is the correct answer?

4

If D₁ and D₂ be the diameters of driver and driven pulleys, then belt speed is proportional to

A. D₁/D₂

B. D₂/D₁

C. D₁.D₂

D. D₁

What is the correct answer?

4

The height of a Watt's governor is

A. Directly proportional to speed

B. Directly proportional to (speed)²

C. Inversely proportional to speed

D. Inversely proportional to (speed)²

What is the correct answer?

4

In a Hartnell governor, the compression of the spring is __________ the lift of the sleeve.

A. Equal to

B. Less than

C. Greater than

D. None of these