MCQ FRICTION

 

 

 

 

 

 

 

MCQ FRICTION

 MCQ increases the level of understanding

and clarity. Friction is the resistance

offered to motion of one body upon

another body. Frictional force is always

parallel to the surface of contact. It

depends upon the surface roughness.

Friction is a shear force. There are two

types of friction. Static friction develops

between the surfaces of contact of

two bodies at rest when force applied is

insufficient to move the body. The force of

friction between two bodies in motion is

dynamic friction. In the absence of a

lubricant, friction is called solid friction.

  1. The direction of friction is

    1. Parallel to the motion

    2. Opposite to the motion

    3. Perpendicular to the direction of motion

    4. None

ANS: (b)

  1. In static friction, friction force is

    1. Constant

    2. Variable

    3. Can’t say

    4. None

ANS: (b)

  1. When a body is just ready to move, force of friction is

    1. Unlimited

    2. Limited

    3. Can’t say

    4. None

ANS: (b)

  1. The ratio of limiting friction and normal reaction is

    1. Variable

    2. Constant

    3. Both (a) & (b)

    4. None

ANS: (b)

  1. The limiting force of friction depends upon

    1. Shape of surface

    2. Area of surface

    3. Both area and shape of surface

    4. None

ANS: (d)

  1. The force of friction is

    1. Depends on the velocity of sliding

    2. Do not depend upon the velocity of sliding

    3. Can’t say

    4. None

ANS: (b)

  1. Coefficient of friction is

    1. Force of friction/Normal reaction

    2. Normal reaction/Force of Friction

    3. (a) + (b)

    4. None

ANS: (b)

  1. The symbol for the coefficient of friction is

    1. α

    2. β

    3. γ

    4. None

ANS: (d)

  1. The units of coefficient of friction is

    1. kN/m

    2. N/mm

    3. Poise

    4. None

ANS: (d)

  1. Static force of friction is

    1. Less than the kinetic friction

    2. Greater than the kinetic friction

    3. Equal to the kinetic friction

    4. None

ANS: (b)

  1. Angle of friction is

    1. Less than the angle of repose

    2. Greater than the angle of repose

    3. Equal to the angle of repose

    4. None

ANS: (c)

  1. Coefficient of friction (µ) in terms of angle of friction is equal to the

    1. Sin Ф

    2. Cos Ф

    3. Tan Ф

    4. None

ANS: (c)

  1. When a body of weight ‘W’ is just at the point of move up the inclined plane of angle ‘α’.  The force ’P’ inclined at an angle ‘θ’ to the inclined plane, then

    1. Firstly      P = [Sin(α-Ф)/Cos(θ-Ф)] W

    2. Secondly  P = [Sin(α+Ф)/Cos(θ+Ф)] W

    3. Thirdly      P = [Sin(α+Ф)/Cos(θ-Ф)] W

    4. None

ANS: (c)

  1. When a body of weight ‘W’ is just at the point of move down the inclined plane of angle ‘α’.  The force ’P’ inclined at an angle ‘θ’ to the inclined plane, then

    1. Firstly       P = [Sin(α-Ф)/Cos(θ-Ф)] W

    2. Secondly  P = [Sin(α+Ф)/Cos(θ+Ф)] W

    3. Thirdly      P = [Sin(α-Ф)/Cos(θ+Ф)] W

    4. None

ANS: (c)

  1. When a body of weight ‘W’ is just at the point of move up the inclined plane of angle α.  The force ’P’ acting horizontally, then

    1. Firstly       P = W Tan (α—Ф)

    2. Secondly  P = W Sin(α+Ф)

    3. Thirdly      P = W Tan (α+Ф)

    4. None

ANS: (c)

  1. When a body of weight ‘W’ is just at the point of move down the inclined plane of angle α. The force ’P’ acting horizontally, then

    1. Firstly        P = W Tan (α—Ф)

    2. Secondly    P = W Sin(α+Ф)

    3. Thirdly        P = W Tan (α+Ф)

    4. None

ANS: (a)

  1. A wedge consists of

    1. One or two inclined planes

    2. Three or four inclined planes

    3. Five or six inclined planes

    4. None

ANS: (a)

  1. The shape of wedge is

    1. Triangular

    2. Trapezoidal

    3. Both (a) and (b)

    4. None

ANS: (c)

  1. Which type of friction causes wear and tear?

    1. Static friction

    2. Dynamic friction

    3. Both (a) & (b)

    4. None

ANS: (b)

  1. Kinetic friction causes

    1. Wear

    2. Tear

    3. Wear & tear

    4. None

ANS: (c)

  1. Lubrication is of help in case of

    1. Static friction

    2. Dynamic friction

    3. Both (a) & (b)

    4. None

ANS: (c)

  1. Force of friction is

    1. Directly proportional to the applied force

    2. Inversely proportional to the applied force

    3. Equal to the applied force

    4. None

ANS: (a)

  1. Force of friction ’F’ in terms of normal reaction ’N’ is

    1. F >µN

    2. F=µ N

    3. F

    4. None

ANS: (c)

  1. Static force of friction is

    1. Zero

    2. Limiting friction

    3. 0 to limiting friction

    4. None

ANS: (c)

  1. In case of a vibrating body, kinetic friction is

    1. Causing vibrations

    2. Damping the vibrations

    3. Both (a) & (b)

    4. None

ANS: (b)

  1. The friction was invented by

    1. Newton

    2. Einstein

    3. Coulomb

    4. None

ANS: (c)

  1. The friction between two layers of moving fluid is

    1. Surface tension

    2. Viscosity

    3. Pressure

    4. None

ANS: (b)

  1. Internal friction is in case of

    1. Stress

    2. Strain

    3. Modulus

    4. None

ANS: (a)

  1. Friction causes a

    1. Mechanical energy

    2. Magnetic energy

    3. Chemical energy

    4. None

ANS: (d)

  1. Energy caused by friction is

    1. Internal energy

    2. External energy

    3. Thermal energy

    4. None

ANS: (c)

  1. Friction reduces by the use of

    1. Air

    2. Water

    3. Oil

    4. None

ANS: (c\)

  1. Static friction causes

    1. Potential energy

    2. Kinetic energy

    3. Thermal energy

    4. None

ANS: (d)

  1. Work done by kinetic friction is

    1. Positive

    2. Negative

    3. Neutral

    4. None

ANS: (b)

  1. When brakes are applied in a vehicle, its kinetic energy is converted into

    1. Potential energy

    2. Electrical energy

    3. Magnetic energy

    4. None

ANS: (d)

  1. Friction is measured with a

    • Profilograph

    • Tribometer

    • Turbo meter

    • None

ANS: (b)

  1. Surface roughness is measured with a

    • Profilograph

    • Tribometer

    • Turbo meter

    • None

ANS: (a)