Mechanical Engineering Quiz # 41

Allen bolts are

Self locking bolts

Designed for shock load

Used in aircraft application

Provided with hexagonal depression in head

Uniform strength bolts

The resultant axial load on a bolt depends on

Initial tension

External load applied

Relative elastic yielding (springness) of the bolt and the connected member

And above

(a), and above

The connecting rod bolts are tightened up so that tightening stress

Is just sufficient to hold parts together

Approaches yield point

Is 50% of yield point

Is about yield point divided by safety factor

None of the above

The connecting rod bolts are tightened up with initial tension greater than the external load so that

Joint may not open up

Bolts are weakest elements

The resultant load on the bolt would not be affected by the external cyclic load

Bolts will not loosen during service

None of the above

If an application calls for stresses on screw threads in one direction only, then the following type of thread would be best suited

Square

Acme

Buttress

BSW

Metric

When a bolt is subjected to shock loading, the resilience of the bolt should be considered in order to prevent breakage at

Shank

Head

In the middle

At the thread

Anywhere in the bolt

The shock absorbing capacity of a bolt can be increased by

Tightening it properly

Increasing shank diameter

Grinding the shank

Using washer

Making shank diameter equal to core diameter of thread

Which of the following in power screws is the correct equation for torque if the load is lowered while designing a machine? ( W: Weight in N, θ: Angle of inclination, ϕ: Friction angle)

W tan (θ / ϕ)

W tan (θ x ϕ)

W tan (θ + ϕ)

W tan (θ – ϕ)

Which of the following is a dominance of power screw?

Large load carrying capacity

High efficiency

Wear of screw is reduced

Mechanical advantage is lowered

What is the maximum shear stress for a material of ultimate tensile strength (Sut) with keyway effect according to ASME code?

0.18 Sut

0.135 Sut

0.30 Sut

0.225 Sut

Which of the following elements transfers torque and is only subjected with the bending moment?

Brake

Clutch

Axle

Belt drive

Which of the following joins two rotating shafts to each other?

Key

Coupling

Gear

Belt drive

Which of the following line is the most economical?

Goodman line

Soderberg line

Gerber parabola

Lagrange line

Which of the following expression is not correct for designing a shaft according to rigidity?

T = GθJ / L

J = TL / Gθ

θ = TL / GJ

L = GθT / J

Which of the following is not a type of transmission shaft?

Crankshaft

Countershaft

Transmission shaft

Line shaft

In machine design, which of the following is not true for rigid and flexible couplings?

Rigid couplings are expensive than flexible couplings

Flexible couplings can tolerate any slight misalignment between axes of shafts

Flexible couplings can absorb shocks and vibrations

Rigid couplings cannot tolerate slight misalignment between axes of shafts

Which is not a possible type of failure in a riveted joint?

Crushing failure of the plate

Shear failure of rivet

Tensile failure of the plate between rivets

Shear failure of plate

Which of the following is true about the roller bearing in comparison with ball bearing?

Power lost in friction is more

Axial dimensions are less

Radial dimensions are more

They have point contact

Which of the following correctly symbolizes a fillet joint?

A right angled triangle

Two parallel lines with an arc above them

A triangle with an arc above it

A triangle

Which of the following is not a type of welding joint?

Lap joint

Butt joint

Tee joint

Single strap joint

Which of the following is the function of rebound clips in a multi-leaf spring?

Helps to share the load from master leaf to graduated leaves

Hold all the leaves of the spring

Engage the bolts to clamp the leaves

Attach a member or component to

In which of the following type of lever the effort is located between the load and fulcrum?

First type

Second type

Third type

Fourth type

Which of the following is not the cause of stress concentration?

Abrupt changes in cross-section

Discontinuity in the component

Machining scratches

Point load applied on the component

Which of the following straight-line joins endurance limit(Se) on the stress amplitude axis and yield strength (Syt) on the mean stress axis?

Soderberg line

Modified goodman line

Gerber line

Goodman line

Which of the following shaft are the integrals or equally spaced lines made on a shaft?

Stepped shaft

Spline shaft

Cam shaft

Crankshaft

Which of the following is not the method to reduce stress concentration?

Usage of additional notches and holes

Usage of fillet radius

Usage of additional discontinuities

Usage of sharp corners

Which of the following is not a type of sunk key?

Gib headed key

Woodruff key

Square key

Hollow saddle key

Which of the following is not the function of a spring?

They are used for the measurement of force and to control motion

They are used to absorb shocks and vibrations

They are used to store energy

They are used to measure displacement

Which of the following materials are subjected to the most severe stress concentration?

Ductile materials under fluctuating load

Brittle materials under static and fluctuating load

Brittle materials under fluctuating load

Ductile materials under static load

Which of the following is not true for a good coupling?

It should be capable for transmitting power from one shaft to another

It should keep shafts in proper alignment

It should be easy to assemble and disassemble for repair and maintenance

If there is small misalignment between the shafts, the coupling cannot transmit power