In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the steam lap and the angle of advance of the eccentric but keeping constant the travel and lead of the valve, this method will
Cause withdrawing or throttling of steam
Reduce length of effective stroke of piston
Reduce maximum opening of port to steam
All of these
Correct Answer :
C. Reduce maximum opening of port to steam
Related Questions
In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve is by increasing the angle of advance of the eccentric while the throw of the eccentric, steam lap and exhaust lap are kept constant. This method will
Cause withdrawing or throttling of steam
Reduce length of effective stroke of piston
Reduce maximum opening of port to steam
All of these
The length of a simple pendulum which gives the same frequency as the compound pendulum, is
kG + l₁
kG² + l₁
(kG² + l₁²)/ l₁
(kG + l₁²)/ l₁
The critical speed of a shaft in revolution per second is __________ as that of natural frequency of transverse vibration.
Same
Different
Unpredictable
None of these
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
1.4 N-s/m
18.52 N-s/m
52.92 N-s/m
529.2 N-s/m
Coriolis component acts
Perpendicular to sliding surfaces
Along sliding surfaces
Somewhere in between above two
None of the above
Which of the following is a higher pair?
Turning pair
Screw pair
Belt and pulley
None of the above
The unbalanced force due to reciprocating masses
Varies in magnitude but constant in direction
Varies in direction but constant in magnitude
Varies in magnitude and direction both
Constant in magnitude and direction both
In a circular arc cam with roller follower, the acceleration in any position of the lift will depend only upon
Total lift, total angle of lift, minimum radius of cam and cam speed
Radius of circular arc, cam speed, location of centre of circular arc and roller diameter
Mass of cam follower linkage, spring stiffness and cam speed
Total lift, centre of gravity of the cam and cam speed
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
Which of the following governor is used to drive a gramophone?
Watt governor
Porter governor
Pickering governor
Hartnell governor
The relation between number of links (l) and number of joints (j) in a kinematic chain is
l = (1/2).(j + 2)
l = (2/3).(j + 2)
l = (3/4).(j + 3)
l = j + 4
A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if
The sum of the two masses is equal to the total mass of body
The centre of gravity of the two masses coincides with that of the body
The sum of mass moment of inertia of the masses about their centre of gravity is equal to the mass moment of inertia of the body
All of the above
The frictional torque transmitted in a conical pivot bearing, considering uniform pressure, is (where R = Radius of shaft, and α = Semi-angle of the cone)
(1/2) μ W R cosecα
(2/3) μ W R cosecα
(3/4) μ W R cosecα
μ W R cosecα
The Grubler's criterion for determining the degrees of freedom (n) of a mechanism having plane motion is (where l = Number of links, and j = Number of binary joints)
n = (l -1) - j
n = 2(l - 1) - 2j
n = 3(l - 1) - 2j
n = 4(l - 1) - 3j
A body in motion will be subjected to coriolis acceleration when that body is
In plane rotation with variable velocity
In plane translation with variable velocity
In plane motion which is a resultant of plane translation and rotation
Restrained to rotate while sliding over another body
The equation of motion for a vibrating system with viscous damping is (d²x/dt²) + (c/m).(dx/dt) + (s/m).x = 0, if the roots of the equation are __________ then the system will be under damped.
Equal
Real
Complex conjugate
None of these
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
3
4
5
Klein's construction can be used to determine acceleration of various parts when the crank is at
Inner dead centre
Outer dead centre
Right angles to the link of the stroke
All of the above
A simple spring-mass vibrating system has a natural frequency of fn. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
fn/2
2 fn
4 fn
8 fn
If the pressure angle is __________, a reciprocating follower will jam in its bearings.
Small
Too small
Large
Too large
The equation of free vibrations of a system is (d²x/dt²) +36 π²x, its natural frequency is
3 Hz
3π Hz
6 Hz
6π Hz
When there is a reduction in amplitude over every cycle of vibration, then the body is said to have
Free vibration
Forced vibration
Damped vibration
Under damped vibration
Critical damping is a function of
Mass and stiffness
Mass and damping coefficient
Mass and natural frequency
Damping coefficient and natural frequency
The contact ratio is given by
(Length of the path of approach)/(Circular pitch)
(Length of path of recess)/(Circular pitch)
(Length of the arc of contact)/(Circular pitch)
(Length of the arc of approach)/cosφ
The maximum frictional force, which comes into play, when a body just begins to slide over the surface of the other body, is known as
Static friction
Dynamic friction
Limiting friction
Coefficient of friction
When the speed of the engine fluctuates continuously above and below the mean speed, the governor is said to be
Stable
Unstable
Isochronous
Hunt
In a steam engine, the link constitutes a
Piston, piston rod and crosshead
Connecting rod with big and small end brasses, caps and bolts
Crank pin, crankshaft and flywheel
All of the above
Coriolis component is encountered in
Quick return mechanism of shaper
Four bar chain mechanism
Slider crank mechanism
Both (A) and (C) above
A point on a link connecting double slider crank chain traces a
Ellipse
Circle
Parabola
Hyperbola
In a steam engine, the distance by which the outer edge of the Dslide valve overlaps the steam port is called
Lead
Steam lap
Exhaust lap
None of these