Home
Current Affairs January 2024

What is the correct answer?

4

Kinetic friction is the

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

B. Ratio of limiting friction and normal reaction

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

D. The friction force acting when the body is in motion

Correct Answer :

D. The friction force acting when the body is in motion


Related Questions

What is the correct answer?

4

From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the centre of circular plate

A. 0.5 cm

B. 1.0 cm

C. 1.5 cm

D. 2.5 cm

What is the correct answer?

4

A projectile is fired at an angle θ to the vertical. Its horizontal range will be maximum when θ is

A.

B. 30°

C. 45°

D. 60°

What is the correct answer?

4

The maximum efficiency of a screw jack is

A. (1 - sinφ)/(1 + sinφ)

B. (1 + sinφ)/(1 - sinφ)

C. (1 - tanφ)/(1 + tanφ)

D. (1 + tanφ)/(1 - tanφ)

What is the correct answer?

4

The maximum acceleration of a particle moving with simple harmonic motion is

A. ω

B. ωr

C. ω2r

D. ω/r

What is the correct answer?

4

The coefficient of restitution for inelastic bodies is

A. Zero

B. One

C. Between zero and one

D. More than one

What is the correct answer?

4

The resultant of two forces P and Q (such that P > Q) acting along the same straight line, but in opposite direction, is given by

A. P + Q

B. P - Q

C. P / Q

D. Q / P

What is the correct answer?

4

The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction.)

A. α = 45° + φ/2

B. α = 45° - φ/2

C. α = 90° + φ

D. α = 90° - φ

What is the correct answer?

4

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

A. Zeroth order

B. First order

C. Second order

D. Third order

What is the correct answer?

4

Coulomb friction is the friction between

A. Bodies having relative motion

B. Two dry surfaces

C. Two lubricated surfaces

D. Solids and liquids

What is the correct answer?

4

The velocity ratio of a differential wheel and axle with D as the diameter of effort wheel and d1 and d2 as the diameters of larger and smaller axles respectively, is

A. D/(d₁ + d₂)

B. D/(d₁ - d₂)

C. 2D/(d₁ + d₂)

D. 2D/(d₁ - d₂)

What is the correct answer?

4

The moment of inertia of a solid cone of mass m and base radius r about its vertical axis is

A. 3mr2/5

B. 3mr2/10

C. 2mr2/5

D. 4mr2/5

What is the correct answer?

4

The total motion possessed by a body, is called

A. Impulsive force

B. Mass

C. Weight

D. Momentum

What is the correct answer?

4

A framed structure is perfect, if the number of members are __________ (2j - 3), where j is the number of joints.

A. Equal to

B. Less than

C. Greater than

D. None 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

A. r/2

B. 2r/3

C. r/A

D. 3r/2

What is the correct answer?

4

The coefficient of friction depends upon

A. Nature of surfaces

B. Area of contact

C. Shape of the surfaces

D. All of the above

What is the correct answer?

4

The forces, which meet at one point and their lines of action also lie on the same plane, are known as

A. Coplanar concurrent forces

B. Coplanar non-concurrent forces

C. Non-coplanar concurrent forces

D. Non-coplanar non-concurrent forces

What is the correct answer?

4

The moment of inertia of a square of side a about its diagonal is

A. a2/8

B. a3/12

C. a4/12

D. a4/16

What is the correct answer?

4

The force required to move the body up the plane will be minimum if it makes an angle with the inclined plane __________ the angle of friction.

A. Equal to

B. Less than

C. Greater than

D. None of these

What is the correct answer?

4

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

A. Area of the triangle

B. Twice the area of the triangle

C. Half the area of the triangle

D. None of these

What is the correct answer?

4

The units of moment of inertia of mass are

A. kg-m²

B. m²/kg.

C. kg/m²

D. kg/m

What is the correct answer?

4

If a number of forces act simultaneously on a particle, it is possible

A. Not a replace them by a single force

B. To replace them by a single force

C. To replace them by a single force through C.G.

D. To replace them by a couple

What is the correct answer?

4

The total momentum of a system of masses (i. e. moving bodies) in any one direction remains constant, unless acted upon by an external force in that direction. This statement is called

A. Newton's first law of motion

B. Newton's second law of motion

C. Principle of conservation of energy

D. Principle of conservation of momentum

What is the correct answer?

4

If the number of pulleys in a system is equal to its velocity ratio, then it is a __________ system of pulleys

A. First

B. Second

C. Third

D. None of these

What is the correct answer?

4

The C.G. of a solid hemisphere lies on the central radius 3r

A. At distance from the plane base 3r

B. At distance from the plane base 3r

C. At distance from the plane base 3r

D. At distance from the plane base

What is the correct answer?

4

Which of the following are vector quantities?

A. Linear displacement

B. Linear velocity

C. Linear acceleration

D. All of these

What is the correct answer?

4

A force while acting on a body may

A. Change its motion

B. Balance the forces, already acting on it

C. Give rise to the internal stresses in it

D. All of these

What is the correct answer?

4

The Cartesian equation of trajectory is (where u = Velocity of projection, α = Angle of projection, and x, y = Co-ordinates of any point on the trajectory after t seconds.)

A. y = (gx²/2u² cos²α) + x. tanα

B. y = (gx²/2u² cos²α) - x. tanα

C. y = x. tanα - (gx²/2u² cos²α)

D. y = x. tanα + (gx²/2u² cos²α)

What is the correct answer?

4

Pick up the incorrect statement from the following:

A. The C.G. of a circle is at its centre

B. The C.G. of a triangle is at the intersection of its medians

C. The C.G. of a rectangle is at the intersection of its diagonals

D. The C.G. of a semicircle is at a distance of r/2 from the centre

What is the correct answer?

4

The time of flight of a projectile on downward inclined plane depends upon

A. Angle of projection

B. Angle of inclination of the plane

C. Both (A) and (B)

D. None of these

What is the correct answer?

4

The centre of gravity of a right circular solid cone is at a distance of __________ from its base, measured along the vertical axis. (where h = Height of a right circular solid cone.)

A. h/2

B. h/3

C. h/4

D. h/6