Deck 7: Mechanical Engineering: Higher Pairs, Kinematic Chains, Vibrating Bodies

Question 1

In case of higher pairs

A)There is contact only at higher point of the two elements while in motion
B)There is only line or point contact between the two elements while in motion
C)There is only line or point contact between the two elements while in motion.
D)There is no contact between the two elements
E)None of the above

Answer 1

There is only line or point contact between the two elements while in motion

Question 2

When one of the links of a kinematic chain is fixed it is known as

A)structure
B)mechanism
C)machine
D)None of the above
E)None of the above.

Answer 2

mechanism

Question 3

Dynamically unbalanced masses in rotating machines cause

A)Noise
B)Friction
C)Wear
D)Vibrations
E)All of the above

Answer 3

Vibrations

Question 4

Which of the following are not standard forms for spur-gears?

A)14
B)14.
C)20°full depth involute system
D)20° stub-tooth involute system
E)All above

Question 5

A stretched string of a guitar when operated is subjected to

A)Free vibrations
B)Forced torsional vibrations
C)Forced transverse vibrations
D)Damped vibrations
E)None of the above

Question 6

A vibrometer

A)Indicates vibration frequency
B)Only indicates second and above harmonics
C)Indicates vibration amplitude
D)Indicates nature of vibrations
E)Indicates wave from vibrations

Question 7

For fluctuating loads, the appropriate bearing would be

A)Roller bearing
B)Ball bearing
C)Bush bearing
D)Ball bearing with sleeve
E)Needle roller bearing

Question 8

In case of belt drives, the effect of centrifugal tension is

A)To reduce the driving power
B)To increase the driving power
C)Not appreciable on driving power
D)Dependent on other factors
E)None of the above

Question 9

In case of instantaneous centre of rotation

A)Only three rigid links have no linear velocities relative to each other
B)Two rigid links rotate instantaneously relative to each other
C)One rigid link has no linear velocity
D)The two rigid links have no linear velocities relative to each other at the instantaneous centre
E)None of the above

Question 10

The pitch circle of a cam is

A)The smallest circle drawn to the pitch curve from the centre of rotation of curve
B)The smallest circle drawn to the cam profile from the centre of rotation of a radial cam
C)The circle fitting in cam profile
D)The circle with centre as the centre of cam axis and radius such that it passes through the pitch point
E)None of the above

Question 11

The standard pressure angle is generally

A)22°
B)10°
C)12°
D)14°
E)17°

Question 12

Frequency of oscillation of a compound pendulum having the same distance between point of suspension and the centre of gravity of mass as a simple pendulum will be

A)Less
B)Same
C)More
D)Depends on other parameters
E)None of the above

Question 13

Which is the false statement about a governor?

A)Isochronism in govrnors is desirable when approximately one constant speeds is desired to be kept for all loads
B)A very sensitive governor may not be very stable
C)A sensitive governor cannot be isochronous
D)Hunting in a governor may occur due to worn out guides of the sleeve
E)A stable governor has a fixed position of balls for each speed within the working range

Question 14

The angle of obliquity is kept small in order

A)To reduce force of friction
B)To minimise axial load
C)To minimise power loss in gearing
D)To avoid larger throusts
E)None of the above

Question 15

If there are L number of links in a mechanism, then the number of possible inversions would be

A)(L + 2)
B)(L + 3)
C)L/2
D)L
E)(L + 1)

Question 16

A mechanism is an assembly of

A)two links
B)three links
C)only four links
D)four or more than four links
E)None of the above

Question 17

A gear box in an automobile utilises

A)Simple gear train
B)Compound gear train
C)Epicyclic gear train
D)Compound-epicyclic gear train
E)None of the above

Question 18

In the coupling rod mechanism of a locomotive each of the four pairs is a

A)sliding pair
B)Rolling pair
C)screw pair
D)Turning pair
E)All of the above

Question 19

At critical speed

A)The shaforuns smoothly
B)The shaft runs with noise due to vibrations
C)The shaft becomes dynamically unstable with negligible lateral amplitudes
D)The shaft becomes dynamically unstable with large lateral amplitudes
E)None of the above

Question 20

When sunk key is to be used the key way is

A)Provided in shaft only
B)36 Hz
C)Provided both in shaft and hub
D)Keyway is not provided for a sunk key
E)Provided in hub only

Question 21

Kinetic friction is

A)That which occurs when there is no motion
B)Less than maximum static friction
C)Is equal to the static friction
D)Is always more than peak static friction
E)That occurs on dry surfaces only

Question 22

Coriolis component of acceleration will exist only if

A)There are two coincidental points
B)Two coincident points have relative angular velocity of sliding
C)Two coincidental points have linear relative velocity of sliding accompanied by the rotation about fixed centres
D)The two coincidental points must have same centre of rotation
E)None of the above

Question 23

In a car, transmission losses will be minimum in

A)First gear
B)Direct gear
C)Second gear
D)Sperm
E)Third gear