Mechanical Engineering Quiz # 44

The force in BD of the truss shown in below figure is:

500 kg compressive

500 kg tensile

1500 kg tensile

1500 kg compressive

During a tensile test on a ductile material

Nominal stress at fracture is higher than the ultimate stress

True stress at fracture is higher than the ultimate stress

True stress at fracture is the same as the ultimate stress

None of these

A framed structure is perfect if it contains members equal to

2n

3

Nl

2nl

3n²

When equal and opposite forces applied to a body, tend to elongate it, the stress so produced, is called

Shear stress

Compressive stress

Tensile stress

Transverse stress

A joint of a frame is subjected to three tensile forces P, Q and R equally inclined to each other. If P is 10 tonnes, the other forces will be

Q = 10 tonnes and R = zero

R + 10 tonnes and Q = zero

Q + R = 10 tonnes

Q and R each is equal to 10 tonnes

In the equation of virtual work, following force is neglected

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

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

Reaction at a point or an axis, fixed in space, around which a body is constrained to turn

All of the above

The structure shown in below figure is stable, if

X y/2

X = 2y

= y

X) = y

Pick up the correct statement from the following:

The rate of change of bending moment is equal to rate of shear force

The rate of change of shear force is equal to rate of loading

Neither nor

Both and

Tangent of angle of friction is equal to

Kinetic friction

Limiting friction

Angle of repose

Coefficient of friction

The type of butt joints in common use, is:

Single inverted V-butt joint

Double V-butt joint

Double U-butt joint

Single V-butt joint

For keeping the stress wholly compressive the load may be applied on a circular column anywhere within a concentric circle of diameter

D/2

D/3

D/4

D/8

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

At distance from the plane base 3r

At distance from the plane base 3r

At distance from the plane base 3r

At distance from the plane base or

In a loaded beam, the point of contraflexure occurs at a section where

Bending moment is minimum

Bending moment is zero or changes sign

Bending moment is maximum

Shearing force is maximum

In actual machines

Mechanical advantage is greater than velocity ratio

Mechanical advantage is equal to velocity ratio

Mechanical advantage is less than velocity ratio

Mechanical advantage is unity

In the given below figure, the rivets with maximum stress, are:

1 and 2

1 and 3

3 and 4

2 and 4

If two forces acting at a joint are not along the straight line, then for the equilibrium of the joint

One of the forces must be zero

Each force must be zero

Forces must be equal and of the same sign

Forces must be equal in magnitude but opposite in sign

Shear deflection of a cantilever of length L, cross sectional area A and shear modulus G, under a concentrated load W at its free end, is

(2/3) (WL/AG)

(1/3) (WL²/EIA)

(3/2) (WL/AG)

(3/2) (WL²/AG)

Forces are called concurrent when their lines of action meet in

One point

Two points

Plane

Perpendicular planes

The ratio of the maximum deflections of a beam simply supported at its ends with an isolated central load and that of with a uniformly distributed load over its entire length, is

3/2

15/24

24/15

2/3

At either end of a plane frame, maximum number of possible bending moments, are

Zero

One

Two

Three

Which of the following is not the unit of work, energy and heat?

Kcal

Kg m

KWhr

Hp

If a shaft is rotating N revolutions per minute with an applied torque T kg-m, the horse power being transmitted by the shaft, is

2 /550

2 /750

2 /4500

2 /55

In a shaft shear stress intensity at a point is not

Directly proportional to the distance from the axis

Inversely proportional to the distance from the axis

Inversely proportional to the polar moment of inertia

Directly proportional to the applied torque

Center of gravity of a solid cone lies on the axis at the height

One-fourth of the total height above base

One-third of the total height above base

One-half of the total height above base

Three-eighth of the total height above the base

The force in DB of the truss shown in below figure is

W compression

W tension

2 W compression

5 W tension

A diagram which shows the variations of the axial load for all sections of the span of a beam, is called

Bending moment diagram

Shear force diagram

Thrust diagram

Stress diagram

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

A cantilever beam rectangular in cross-section is subjected to an isolated load at its free end. If the width of the beam is doubled, the deflection of the free end will be changed in the ratio of

8

1/8

1/2

3

In rectangular columns (cross-section b × h), the core is a

Rectangle of lengths b/2 and h/2

Square of length b/2

Rhombus of length h/2

Rhombus of diagonals b/3 and h/3

Pick up the correct assumption of the theory of simple bending

The value of the Young's modulus is the same in tension as well as in compression

Transverse section of a beam remains plane before and after bending

The material of the beam is homogeneous and isotropic

All the above