The velocity ratio for the third system of pulleys is
n
n²
2n
2n - 1
Correct Answer :
D. 2n - 1
Related Questions
If the resultant of two equal forces has the same magnitude as either of the forces, then the angle between the two forces is
30°
60°
90°
120°
The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of
Friction
Limiting friction
Repose
Kinematic friction
Moment of inertia is the
Second moment of force
Second moment of area
Second moment of mass
All of these
Which one of the following statements is not correct?
The tangent of the angle of friction is equal to coefficient of friction
The angle of repose is equal to angle of friction
The tangent of the angle of repose is equal to coefficient of friction
The sine of the angle of repose is equal to coefficient to friction
The power developed by a body acted upon by a torque T Newton metre (N - m) and revolving at ω radian/s is given by
T.ω (in watts)
T.ω/60 (in watts)
T.ω/75 (in kilowatts)
T.ω/4500 (in kilowatts)
The force induced in the string AB due to the load W, as shown in the below figure is 
W sinθ
W cosθ
W secθ
W cosecθ
One watt is equal to
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1 joule/s
10 joules/s
100 joules/s
The friction experienced by a body, when in motion, is known as
Rolling friction
Dynamic friction
Limiting friction
Static friction
Which of the following is a scalar quantity?
Force
Speed
Velocity
Acceleration
The velocity ratio for the third system of pulleys is
n
n²
2n
2n - 1
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a = α/ r
a = α.r
a = r / α
None of these
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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
Two balls of equal mass and of perfectly elastic material are lying on the floor. One of the balls with velocity v is made to strike the second ball. Both the balls after impact will move with a velocity
v
v/2
v/4
v/8
The impact between two lead spheres is approximately equal to an __________ impact.
Elastic
Inelastic
Solid
None of these
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The two bodies will momentarily come to rest after collision
The two bodies tend to compress and deform at the surface of contact
The two bodies begin to regain their original shape
All of the above
A block of mass m1, placed on an inclined smooth plane is connected by a light string passing over a smooth pulley to mass m2, which moves vertically downwards as shown in the below figure. The tension in the string is 
m1/m2
m1. g. sin α
m1.m2/m1 + m2
m1. m2.g (1 + sin α)/(m1 + m2)
Effect of a force on a body depends upon
Magnitude
Direction
Position or line of action
All of the above
Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction
Along the plane
Horizontally
Vertically
At an angle equal to the angle of friction to the inclined plane
In a screw jack, the effort required to lift the load is given by (where W = Load lifted, α = Helix angle, and φ = Angle of friction.)
P = W tan (α - φ)
P = W tan (α + φ)
P = W tan (φ - α)
P = W cos (α + φ)
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50
100
200
400
The moment of inertia of a rectangular section 3 cm wide and 4 cm deep about X-X axis is
9 cm4
12 cm4
16 cm4
20 cm4
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Coplanar non-concurrent forces
Non-coplanar concurrent forces
Non-coplanar non-concurrent forces
Intersecting forces
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N-m
m/s
m/s2
rad/s2
The centre of percussion is below the centre of gravity of the body and is at a distance equal to
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h2/kG
kG2/h
h × kG
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kilogram
Newton
Watt
Dyne
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ω/r
ω.r
ω2/r
ω2.r
The product of either force of couple with the arm of the couple is called
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Moment of the forces
Resulting couple
Moment of the couple
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
A particle inside a hollow sphere of radius r, having coefficient of friction μ can rest up to height of
r/2
r/A
r/3
0.134 r
Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to
Area of the triangle
Twice the area of the triangle
Half the area of the triangle
None of these