# Mechanics & Strength of Materials 7

Objective Questions and Answer: Mechanics & Strength of Materials 7

Subject:  Mechanics & Strength of Materials 7

Part 7: Objective questions and answers of Mechanics & Strength of Materials

Q1. 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 center of circular plate

a) 0.5 cm

b) 1.0 cm

c) 1.5 cm

d) 2.5 cm

Q2. Pick up the incorrect statement from the following :

a) The C.G. of a circle is at its center

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

c) The C.G. of a rectangle is at the inter-section of its diagonals

d) The C.G. of a semicircle is at a distance of r/2 from the center

Q3. The center 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

Q4. In the equation of virtual work, following force is neglected

a) Reaction of any smooth surface with which the body is in contact

b) Reaction of a rough surface of a body which rolls on it without slipping

c) Reaction at a point or an axis, fixed in space, around which a body is con-strained to turn

d) All of the above

Q5. If a suspended body is struck at the center of percussion, then the pressure on die axis passing through the point of suspension will be

a) Maximum

b) Minimum

c) Zero

d) Infinity

Q6. 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

a) 20 kg, – ve sense

b) 20 kg, + ve sense

c) 10 kg, + ve sense

d) 10 kg, – ve sense

Q7. Angle of friction is the

a) Angle between normal reaction and the resultant of normal reaction and the limiting friction

b) Ratio of limiting friction and normal reaction

c) The ratio of minimum friction force to the friction force acting when the body is just about to move

d) The ratio of minimum friction force to friction force acting when the body is in motion

Q8. The coefficient of friction depends on

a) Area of contact

b) Shape of surfaces

c) Strength of surfaces

d) Nature of surface

Q9. Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction

a) Along the plane

b) Horizontally

c) Vertically

d) At an angle equal to the angle of friction to the inclined plane

Q10. The ratio of limiting friction and normal reaction is known as

a) Coefficient of friction

b) Angle of friction

c) Angle of repose

d) Sliding friction

Q11. Which one of the following statements is not correct

a) The tangent of the angle of friction is equal to coefficient of friction

b) The angle of repose is equal to angle of friction

c) The tangent of the angle of repose is equal to coefficient of friction

d) The sine of the angle of repose is equal to coefficient to friction

Q12. 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

Q13. On the ladder resting on the ground and leaning against a smooth vertical wall, the force of friction will be

a) Downwards at its upper end

b) Upwards at its upper end

c) Perpendicular to the wall at its upper end

d) Zero at its upper end

Q14. Frictional force encountered after commencement of motion is called

a) Post friction

b) Limiting friction

c) Kinematic friction

d) Dynamic friction.

Q15. Coefficient of friction is the

a) 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

Q16. Pick up wrong statement about friction force for dry surfaces. Friction force is

a) Proportional to normal load between the surfaces

b) Dependent on the materials of contact surface

c) Proportional to velocity of sliding

d) Independent of the area of contact surfaces

Q17. In ideal machines

a) Mechanical advantage is greater than velocity ratio

b) Mechanical advantage is equal to velocity ratio

c) Mechanical advantage is less than velocity ratio

Q18. A particle moves along a straight line such that distance (x) traversed in t seconds is given by x = t2 (t – 4), the acceleration of the particle will be given by the equation

a) 3t2-lt

b) 3t2+2t

c) 6f-8

d) 6f-4

Q19. If rain is falling in the opposite direction of the movement of a pedestrian, he has to hold his umbrella

a) More inclined when moving

b) Less inclined when moving

c) More inclined when standing

d) Less inclined when standing

Q20. A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is

a) 0°

b) 30°

c) 45°

d) 60°

Part 7: Objective questions and answers of Mechanics & Strength of Materials