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4

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.)

A. P = W tanα

B. P = W tan (α + φ)

C. P = W (sinα + μcosα)

D. P = W (cosα + μsinα)

Correct Answer :

C. P = W (sinα + μcosα)


Related Questions

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4

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

A. v

B. v/2

C. v/4

D. v/8

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4

The force induced in the string AB due to the load W, as shown in the below figure is

A. W sinθ

B. W cosθ

C. W secθ

D. W cosecθ

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4

Which of the following are vector quantities?

A. Angular displacement

B. Angular velocity

C. Angular acceleration

D. All of these

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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

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4

According to Newton's first law of motion,

A. Everybody continues in its state of rest or of uniform motion, in a straight line, unless it is acted upon by some external force

B. The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts

C. To every action, there is always an equal and opposite reaction

D. None of the above

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4

If three forces acting in different planes can be represented by a triangle, these will be in

A. Non-equilibrium

B. Partial equilibrium

C. Full equilibrium

D. Unpredictable

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4

Coplanar concurrent forces are those forces which

A. Meet at one point, but their lines of action do not lie on the same plane

B. Do not meet at one point and their lines of action do not lie on the same plane

C. Meet at one point and their lines of action also lie on the same plane

D. Do not meet at one point, but their lines of action lie on the same plane

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4

The moment of inertia of a thin disc of mass m and radius r, about an axis through its centre of gravity and perpendicular to the plane of the disc is

A. mr2/2

B. mr2/4

C. mr2/6

D. mr2/8

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4

If P is the force acting on the body, m is the mass of the body and a is the acceleration of the body, then according to Newton's second law of motion,

A. P + m.a = 0

B. P - m.a = 0

C. P × m.a = 0

D. P/m.a = 0

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4

The bodies which rebound after impact are called

A. Inelastic bodies

B. Elastic bodies

C. Neither elastic nor inelastic bodies

D. None of these

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4

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.

A. Less than

B. More than

C. Equal to

D. None of These

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4

The centre of gravity of a triangle lies at the point of

A. Concurrence of the medians

B. Intersection of its altitudes

C. Intersection of bisector of angles

D. Intersection of diagonals

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4

The term 'Centroid' is

A. The same as centre of gravity

B. The point of suspension

C. The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis

D. None of the above

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4

When trying to turn a key into a lock, following is applied

A. Coplanar force

B. Non-coplanar forces

C. Moment

D. Couple

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4

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.)

A. 2π. √(gh/kG² + h²)

B. 2π. √(kG² + h²/gh)

C. 1/2π. √(gh/kG² + h²)

D. 1/2π. √(kG² + h²/gh)

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4

If the resultant of two equal forces has the same magnitude as either of the forces, then the angle between the two forces is

A. 30°

B. 60°

C. 90°

D. 120°

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4

The velocity ratio of a first system of pulleys with 4 pulleys is

A. 4

B. 8

C. 16

D. 20

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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)

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4

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

A. ω

B. ωr

C. ω2r

D. ω/r

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4

A machine having an efficiency less than 50%, is known as

A. Reversible machine

B. Non-reversible machine

C. Neither reversible nor non-reversible machine

D. Ideal machine

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4

The velocity of a particle (v) moving with simple harmonic motion, at any instant is given by (where r = Amplitude of motion, and y = Displacement of the particle from mean position.)

A. ω.√(y² - r²)

B. ω.√(r² - y²)

C. ω².√(y² - r²)

D. ω².√(r² - y²)

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4

According to principle of moments

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

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

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

D. Positive and negative couples can be balanced

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4

The minimum force required to slide a body of weight W on a rough horizontal plane is

A. W sinθ

B. W cosθ

C. W tanθ

D. None of these

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4

The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is known as

A. Principle of independence of forces

B. Principle of resolution of forces

C. Principle of transmissibility of forces

D. None of these

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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

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4

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

A. Towards the wall at its upper end

B. Away from the wall at its upper end

C. Upwards at its upper end

D. Downwards at its upper end

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4

The forces, which meet at one point, but their lines of action do not lie in a plane, are called

A. Coplanar non-concurrent forces

B. Non-coplanar concurrent forces

C. Non-coplanar non-concurrent forces

D. Intersecting forces

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4

Which of the following is not a scalar quantity?

A. Mass

B. Volume

C. Density

D. Acceleration

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4

Tension in the cable supporting a lift is more when the lift is moving __________ with an acceleration.

A. Upwards

B. Downwards

C. Horizontal

D. None of these

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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°