What is the correct answer?

4

# 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

### Correct Answer :

A. 20 kg, -ve sense

### Related Questions

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4

# The acceleration of a body sliding down an inclined surface is

g sinθ

g cosθ

g tanθ

None of these

What is the correct answer?

4

# The potential energy of a vertically raised body is __________ the kinetic energy of a vertically falling body.

Equal to

Less than

Greater than

None of these

What is the correct answer?

4

# Limiting force of friction is the

Tangent of angle between normal reaction and the resultant of normal reaction and limiting friction

Ratio of limiting friction and normal reaction

The friction force acting when the body is just about to move

The friction force acting when the body is in motion

What is the correct answer?

4

# 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

What is the correct answer?

4

# The law of motion involved in the recoil of gun is

Newton's first law of motion

Newton's second law of motion

Newton's third law of motion

None of these

What is the correct answer?

4

# The moment of inertia of a sphere of mass m and radius r, about an axis tangential to it, is

2mr2/3

2mr2/5

7mr2/3

7mr2/5

What is the correct answer?

4

# The velocity ratio for the first system of pulleys is (where n is the number of pulleys.)

n

2n

2n - 1

What is the correct answer?

4

# Mass moment of inertia of a uniform thin rod of mass M and length (l) about its mid-point and perpendicular to its length is

(2/3) Ml2

(1/3) Ml2

(3/4) Ml2

(1/12) Ml2

What is the correct answer?

4

# A lead ball with a certain velocity is made to strike a wall, it falls down, but rubber ball of same mass and with same velocity strikes the same wall, it rebounds. Select the correct reason from the following:

Both the balls undergo an equal change in momentum

The change in momentum suffered by rubber ball is more than the lead ball

The change in momentum suffered by rubber ball is less than the lead ball

None of the above

What is the correct answer?

4

# The range of projectile (R) on an upward inclined plane is

g. cos² β/2u². sin (α + β). cos α

2u². sin (α + β). cos α/g. cos² β

g. cos² β/2u². sin (α - β). cos α

2u². sin (α - β). cos α/g. cos² β

What is the correct answer?

4

# Joule is the unit of

Force

Work

Power

Velocity

What is the correct answer?

4

# If u1 and u2 are the velocities of two moving bodies in the same direction before impact and v1 and v2 are their velocities after impact, then coefficient of restitution is given by

(v1 - v2)/(u1 - u2)

(v₂ - v₁)/(u1 - u2)

(u1 - u2)/(v1 - v2)

(u₂ + u₁)/(v₂ + v₁)

What is the correct answer?

4

# A pair of smith's tongs is an example of the lever of

Zeroth order

First order

Second order

Third order

What is the correct answer?

4

# Frictional force encountered after commencement of motion is called

Limiting friction

Kinematic friction

Frictional resistance

Dynamic friction

What is the correct answer?

4

# A number of forces acting at a point will be in equilibrium, if

All the forces are equally inclined

Sum of all the forces is zero

Sum of resolved parts in the vertical direction is zero (i.e. ΣV = 0)

None of these

What is the correct answer?

4

# Moment of inertia of a hollow rectangular section as shown in the below figure about X-X axis, is

(BD³/12) - (bd³/12)

(DB³/12) - (db³/12)

(BD³/36) - (bd³/36)

(DB³/36) - (db³/36)

What is the correct answer?

4

# The range of a projectile is maximum, when the angle of projection is

30°

45°

60°

90°

What is the correct answer?

4

# According to principle of moments

If a system of coplanar forces is in equilibrium, then their algebraic sum is zero

If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero

The algebraic sum of the moments of any two forces about any point is equal to moment of the resultant about the same point

Positive and negative couples can be balanced

What is the correct answer?

4

# When a person, on a bicycle, drives round a curve, he has to lean __________ to maintain equilibrium.

Inward

Outward

Towards front

Towards back

What is the correct answer?

4

# In order to completely specify angular displacement by a vector, it must fix

Direction of the axis of rotation

Magnitude of angular displacement

Sense of angular displacement

All of these

What is the correct answer?

4

# The centre of percussion of a solid cylinder of radius r resting on a horizontal plane will be

r/2

2r/3

r/A

3r/2

What is the correct answer?

4

# Which of the following is not a vector quantity?

Weight

Velocity

Acceleration

Force

What is the correct answer?

4

# A framed structure is perfect if it contains members equal to

2n³

2n

3n² Where n = number of joints in a frame

What is the correct answer?

4

# Two bodies of masses m1 and m2 are hung from the ends of a rope, passing over a frictionless pulley as shown in the figure below. The acceleration of the string will be

g (m1 - m2)/(m1 + m2)

2g (m1 - m2)/(m1 + m2)

g (m1 + m2)/(m1 - m2)

2g (m1 + m2)/(m1 - m2)

What is the correct answer?

4

# On the ladder resting on the ground and leaning against a smooth vertical wall, the force of friction will be

Downwards at its upper end

Upwards at its upper end

Perpendicular to the wall at its upper end

Zero at its upper end

What is the correct answer?

4

# The moment of the force P about O as shown in the below figure is

P × OA

P × OB

P × OC

P × AC

What is the correct answer?

4

# The forces, whose lines of action are parallel to each other and act in the same directions, are known as

Coplanar concurrent forces

Coplanar non-concurrent forces

Like parallel forces

Unlike parallel forces

What is the correct answer?

4

# The equivalent length of a simple pendulum which gives the same frequency as compound pendulum is

h/(kG² + h²)

(kG² + h²)/h

h²/(kG² + h²)

(kG² + h²)/h²

What is the correct answer?

4

# The algebraic sum of moments of the forces forming couple about any point in their plane is

Equal to the moment of the couple

Constant

Both of above are correct

Both of above are wrong

What is the correct answer?

4

# The centre of gravity of a uniform lamina lies at

The centre of heavy portion

The bottom surface

The midpoint of its axis

All of the above