The maximum mechanical advantage of a lifting machine is
1 + m
1 - m
1 / m
m
Correct Answer :
C. 1 / m
Related Questions
The centre of gravity of a trapezium with parallel sides a and b lies at a distance of y from the base b, as shown in the below figure. The value of y is 
h [(2a + b)/(a + b)]
(h/2) [(2a + b)/(a + b)]
(h/3) [(2a + b)/(a + b)]
(h/3) [(a + b)/(2a + b)]
Which of the following is not the unit of work, energy and heat?
kcal
kg-m
kW-hr
h.p
In ideal machines
Mechanical advantage is greater than velocity ratio
Mechanical advantage is equal to velocity ratio
Mechanical advantage is less than velocity ratio
Mechanical advantage is unity
A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
Circular arc
Parabola
Hyperbola
Elliptical
If a number of forces act simultaneously on a particle, it is possible
Not a replace them by a single force
To replace them by a single force
To replace them by a single force through C.G.
To replace them by a couple
The velocity ratio of a simple wheel and axle with D and d as the diameters of effort wheel and load axle, is
D + d
D - d
D × d
D / d
A body of weight W is required to move up on rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tanφ = Coefficient of friction between the plane and the body.)
P = W tanα
P = W tan (α + φ)
P = W (sinα + μcosα)
P = W (cosα + μsinα)
In a framed structure, as shown in the below figure, the forces in the members AB and BC are respectively 
√3. W (tensile) and 2W (compressive)
2W (tensile) and √3. W (compressive)
2√3. W (tensile) and 2√3. W (compressive)
None of the above
If tension in the cable supporting a lift moving downwards is half the tension when it is moving upwards, the acceleration of the lift is
g/2
g/3
g/4
None of these
If a number of forces are acting at a point, their resultant will be inclined at an angle θ with the horizontal, such that
tanθ = ΣH/ΣV
tanθ = ΣV/ΣH
tanθ = ΣV × ΣH
tanθ = √(ΣV + ΣH)
The centre of gravity a T-section 100 mm × 150 mm × 50 mm from its bottom is
50 mm
75 mm
87.5 mm
125 mm
The range of projectile on a downward inclined plane is ________ the range on upward inclined plane for the same velocity of projection and angle of projection.
Less than
More than
Equal to
None of These
The centre of gravity of a quadrant of a circle lies along its central radius (r) at a distance of
0.5r
0.6 r
0.7 r
0.8 r
Work done is said to be zero, when
Some force acts on a body, but displacement is zero
No force acts on a body but some displacement takes place
Either (A) or (B)
None of the above
When a rigid body is suspended vertically, and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
Coplanar non-concurrent forces are those forces which __________ at one point, but their lines of action lie on the same plane.
Meet
Do not meet
Either A or B
None of these
The principle of transmissibility of forces states that, when a force acts upon a body, its effect is
Same at every point on its line of action
Different at different points on its line of action
Minimum, if it acts at the centre of gravity of the body
Maximum, if it acts at the centre of gravity of the body
Two coplanar couples having equal and opposite moments
Balance each other
Produce a couple and an unbalanced force
Are equivalent
Cannot balance each other
Which of the following is not the unit of pressure?
kg/cm
Bar
Atmosphere
Newton
The resultant of the following three couples 20 kg force, 0.5 m arm, +ve sense 30 kg force, 1 m arm, -ve sense 40 kg force, 0.25 m arm, +ve sense having arm of 0.5 m will be
20 kg, -ve sense
20 kg, + ve sense
10 kg, + ve sense
10 kg, -ve sense
The frequency of oscillation of a compound pendulum is (where kG = Radius of gyration about the centroidal axis, and h = Distance between the point of suspension and C.G. of the body.)
2π. √(gh/kG² + h²)
2π. √(kG² + h²/gh)
1/2π. √(gh/kG² + h²)
1/2π. √(kG² + h²/gh)
During elastic impact, the relative velocity of the two bodies after impact is __________ the relative velocity of the two bodies before impact.
Equal to
Equal and opposite to
Less than
Greater than
Moment of inertia of a rectangular section having width (b) and depth (d) about an axis passing through its C.G. and parallel to the width (b), is
db³/12
bd³/12
db³/36
bd³/36
A rubber ball is dropped from a height of 2 m. If there is no loss of velocity after rebounding, the ball will rise to a height of
1 m
2 m
3 m
4 m
Two like parallel forces are acting at a distance of 24 mm apart and their resultant is 20 N. It the line of action of the resultant is 6 mm from any given force, the two forces are
15 N and 5 N
20 N and 5 N
15 N and 15 N
None of these
A semicircular disc rests on a horizontal surface with its top flat surface horizontal and circular portion touching down. The coefficient of friction between semi circular disc and horizontal surface is μ. This disc is to be pulled by a horizontal force applied at one edge and it always remains horizontal. When the disc is about to start moving, its top horizontal force will
Remain horizontal
Slant up towards direction of pull
Slant down towards direction of pull
None of the above
Centre of gravity of a thin hollow cone lies on the axis at a height of
One-fourth of the total height above base
One-third of the total height above base
One-half of the total height above base
Three-eighth of the total height above the base
The moment of the force P about O as shown in the below figure is 
P × OA
P × OB
P × OC
P × AC
In a framed structure, as shown in the below figure, the force in the member BC is 
W/√3 (compression)
W/√3 (tension)
2W/√3 (compression)
2W/√3 (tension)
Two blocks A and B of masses 150 kg and 50 kg respectively are connected by means of a string as shown in the below figure. The tension in all the three strings __________ be same. 
Will
Will not
Either A or B
None of these