A rotor supported at A and B carries two masses as shown in the below figure. The rotor is 
Dynamically balanced
Statically balanced
Statically and dynamically balanced
Not balanced
Correct Answer :
C. Statically and dynamically balanced
Related Questions
A shaft has two heavy rotors mounted on it. The transverse natural frequencies, considering each of the rotor separately, are 100 Hz and 200 Hz respectively. The lowest critical speed is
5,367 r.p.m.
6,000 r.p.m.
9,360 r.p.m.
12,000 r.p.m.
In a Hartnell governor, the compression of the spring is __________ the lift of the sleeve.
Equal to
Less than
Greater than
None of these
In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
The maximum value of the pressure angle in case of cam is kept as
10°
14°
20°
30°
Which of the following governor is used to drive a gramophone?
Watt governor
Porter governor
Pickering governor
Hartnell governor
The mechanism consisting of three turning pairs and one sliding pair, is called a
Single slider crank chain
Whitworth quick return motion mechanism
Crank and slotted lever quick return motion mechanism
All of the above
Which of the following is a turning pair?
Piston and cylinder of a reciprocating steam engine
Shaft with collars at both ends fitted into a circular hole
Lead screw of a lathe with nut
Ball and a socket joint
The distance by which the __________ of the D-slide valve overlaps the steam port is called exhaust lap.
Inner edge
Outer edge
Corners
None of these
Which of the following is an inversion of Single slider crank chain?
Beam engine
Rotary engine
Oldhams coupling
Elliptical trammel
The example of completely constrained motion is a
Motion of a piston in the cylinder of a steam engine
Motion of a square bar in a square hole
Motion of a shaft with collars at each end in a circular hole
All of the above
In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set to
Reduce vibration
Reduce slip
Ensure uniform loading
Ensure proper alignment
A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the centre of bigger gear is
2
4
3
None of the above
A mechanism __________ for transmitting or transforming motion.
Can be used
Cannot be used
Unpredictable
None of these
A spring controlled governor is said to be isochronous when the controlling force
Increases as the radius of rotation decreases
Increases as the radius of rotation increases
Decreases as the radius of rotation increases
Remain constant for all radii of rotation
In a disc clutch, if there are n₁ number of discs on the driving shaft and n₂ number of discs on the driven shaft, then the number of pairs of contact surfaces will be
n₁ + n₂
n₁ + n₂ + 1
n₁ + n₂ - 1
n₁ + n₂ - 2
The coriolis component of acceleration leads the sliding velocity by
45°
90°
135°
180°
The arrangement is called bevel gearing, when two __________ are connected by gears.
Intersecting and coplanar shafts
Nonintersecting and non-coplanar shafts
Parallel and coplanar shafts
Parallel and non-coplanar shafts
When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be
To move the ship towards starboard
To move the ship towards port side
To raise the bow and lower the stern
To raise the stern and lower the bow
The cam and follower is an example of
Sliding pair
Rolling pair
Lower pair
Higher pair
In a locomotive, the maximum magnitude of the unbalanced force along the perpendicular to the line of stroke, is known as
Tractive force
Swaying couple
Hammer blow
None of these
Sensitiveness of the governor is defined as the ratio of the
Mean speed to the maximum equilibrium speed
Mean speed to the minimum equilibrium speed
Difference of the maximum and minimum equilibrium speeds to the mean speed
Sum of the maximum and minimum equilibrium speeds to the mean speed
The mechanism in which two are turning pairs and two are sliding pairs, is called a
Double slider crank chain
Elliptical trammel
Scotch yoke mechanism
All of these
When the crank is at the inner dead centre, in a reciprocating steam engine, then the velocity of the piston will be
Minimum
Zero
Maximum
None of these
Which one of the following is an exact straight line mechanism using lower pairs?
Watts mechanism
Grasshopper mechanism
Roberts mechanism
Peaucelliers mechanism
In order to double the period of a simple pendulum, the length of the string should be
Halved
Doubled
Quadrupled
None of these
A rigid body possesses ________degrees of freedom
One
Two
Four
Six
Module of a gear is
D/T
T/D
2D/T
2T/D
Which of the following is an inversion of a single slider crank chain?
Pendulum pump
Oscillating cylinder engine
Rotary internal combustion engine
All of these
In under damped vibrating system, if x₁ and x₂ are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to
x₁/x₂
log(x₁/x₂)
loge(x₁/x₂)
log(x₁.x₂)
The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a left turn. The effect of gyroscopic couple acting on it will be
To raise the bow and stern
To lower the bow and stern
To raise the bow and lower the stern
To raise the stern and lower the bow