Explore topic-wise MCQs in Machine Design.

This section includes 509 Mcqs, each offering curated multiple-choice questions to sharpen your Machine Design knowledge and support exam preparation. Choose a topic below to get started.

401.

In case of a knuckle joint the pin is likely to fail in

A. Tension
B. Crushing
C. Double shear
D. Compression
E. Shear
Answer» D. Compression
402.

Extrafine threaded connections are generally recommended for

A. Increasing the diameter of threaded portion
B. Rolled sections
C. hardened objects
D. thin walled assemblies
E. Tapped hole in castings
Answer» E. Tapped hole in castings
403.

The satisfactory method of reclaiming worn out and under sized part subject to fatigue loads is

A. Repainting
B. Polishing
C. Electroplating
D. Recasting
E. None of the above
Answer» D. Recasting
404.

Lubricant is not required in

A. Increasing the diameter of threaded portion
B. Electromagnetic bearing
C. Hydrostatic bearings
D. Gas bearings
E. Foil bearing
Answer» C. Hydrostatic bearings
405.

Shot peening leaves the material surface in

A. residual tensile stress
B. residual shear stress
C. residual compressive stress
D. All of the above
E. Increasing the diameter of threaded portion
Answer» D. All of the above
406.

A material is generally classified as brittle if the percentage elongation (in a gauge length of 50 mm) is less than

A. Chrome steel
B. 1%
C. 2%
D. 5%
E. 15%
Answer» E. 15%
407.

A steel specified as St 50 will have a tensile strength of approximately

A. 50 tonnes/m2
B. 50 kg/mm2
C. 50 kg/cm2
D. 50 tonnes/mm2
E. None of the above
Answer» C. 50 kg/cm2
408.

The holes in plates for reveting are usually made by

A. Arc cutting
B. Oxyacetylene flame
C. Punching
D. Drilling
E. Any of the above
Answer» E. Any of the above
409.

Spigot and socket joints are used on pipes

A. Which are buried underground
B. Carrying air at pressure above atmospheric pressure
C. Carrying steam under high pressure
D. Carrying high pressure fluids under high pressure
E. Carrying air at pressure below atmospheric pressure
Answer» B. Carrying air at pressure above atmospheric pressure
410.

A flange coupling is

A. Used for non-collinear shafts
B. Used for collinear shafts
C. Flexible
D. Used only on small shafts rotating at slow speeds
E. None of the above
Answer» C. Flexible
411.

A stud is

A. Screw with cylindrical head
B. Headless scew
C. Screw with circular heads
D. Oval heads screw
E. Screw with long threads
Answer» C. Screw with circular heads
412.

Dead weight type safety valve is not used on locomotives because

A. It is costly
B. It is susceptible to vibratory forces
C. It is not reliable
D. It is bulky
E. It gives bad apparatus
Answer» C. It is not reliable
413.

The weakest plane in a fillet weld is

A. the throat
B. smaller of the sides
C. side normal to the force
D. side parallel to the force
E. Increasing the diameter of threaded portion
Answer» B. smaller of the sides
414.

In gear design, addendum is equal to

A. Cast steel
B. Twice of module
C. One and a half times module
D. Module
E. Half of module
Answer» E. Half of module
415.

Low pressure angle on gears results in

A. Weaker teeth
B. stronger teeth
C. abrasive wear
D. none of the above
E. Cast steel
Answer» B. stronger teeth
416.

Non-metallic gears have

A. Low noise at higher speeds and low load carrying capacity
B. High noise at higher speeds and high load carrying capacity
C. Low noise at higher speeds and high load carrying capacity
D. Cannot be operated at higher speed.
E. All of the above
Answer» B. High noise at higher speeds and high load carrying capacity
417.

The efficiency of a screw track is maximum when its helix angle '?' is equal to

A. 45 - ?
B. 45 - ?/2
C. Increasing the diameter of threaded portion
D. 45 + ?/2
E. 45?
Answer» C. Increasing the diameter of threaded portion
418.

Which of the following is not the advantage of V-belts over flat belts?

A. Less shock load absorption
B. Less axial space requirement
C. Increasing the diameter of threaded portion
D. Less slippage
E. Less noisy
Answer» C. Increasing the diameter of threaded portion
419.

The following property is the most important for normal used for gas turbine blades

A. Increasing the diameter of threaded portion
B. Resistance to bending
C. Creep
D. Fatigue
E. Resistance to shear
Answer» D. Fatigue
420.

Which of the following is a positive clutch?

A. Increasing the diameter of threaded portion
B. Band cluch
C. Jaw clutch
D. Disc clutch
Answer» D. Disc clutch
421.

When a section of a beam is plastified due to given system of loading then

A. the length of beam over which the moment is geater than or equal to the yield moment is plastified
B. only one section of beam is plastified
C. the whole length of beam is plastified
D. Increasing the diameter of threaded portion
E. the length of beam over which the moment is less than the yield moment is plastified
Answer» B. only one section of beam is plastified
422.

The pitch circle of a cam is

A. The smallest circle drawn to the pitch curve
B. Thesmallest circle drawn to the cam profile from the centre of rotation of a radial cam
C. The circle fitting in the cam profile
D. The circle with centre as the centre of cam axis and radius such that it passes through the point
E. None of the above
Answer» E. None of the above
423.

In case of Vee belt

A. The belt should not touch the bottom of groove in the pulley
B. The belt should touch the bottom of groove in the fulley
C. The efficiency of transmission is less
D. Grooves in the pulley are generally wider than the belt
E. Tension in belt remains constant throughout
Answer» B. The belt should touch the bottom of groove in the fulley
424.

Cold working of materials

A. Increases the fatigue strength
B. Reduces the fatigue strength
C. Does not change fatigue strength
D. Has no effect on fatigue trength
E. None of the above
Answer» B. Reduces the fatigue strength
425.

An induction motor stator is cooled by

A. Air
B. Water
C. Hydrogen
D. Air and water
E. None of the above
Answer» B. Water
426.

The casing of a water pump is generally

A. Made of soft material
B. Made of hard material
C. Made of chilled cast iron for water resistance
D. Made of non-ferrous materials
E. None of the above
Answer» D. Made of non-ferrous materials
427.

The differential equation 10x + 200 x + 810x = 0 describes one degree of freedom system. The system is

A. Oscillatory
B. Having critical damping
C. Having more than critical damping
D. Having less than critical damping
E. None of the above
Answer» D. Having less than critical damping
428.

Normally a spring operates within

A. Visco-elastic limits
B. Plastic limits
C. Para-elastic limits
D. Elasto-plastic limits
E. Elastic limits
Answer» F.
429.

What should be the thickness of a cast iron pipe 45 cm diameter if it is required to sustain 6 kg/sq cm inside pressure ? The maximum stress in the pipe material being limited to 140 kg/cm2

A. 12 mm
B. 10 mm
C. 7.5 mm
D. 5 mm
E. 15 mm
Answer» C. 7.5 mm
430.

Bush bearings are

A. Phosphor bronze
B. Aluminium brass
C. Mild steel
D. White metal alloys
E. None of the above
Answer» E. None of the above
431.

The locomotive wheel tires are fitted as

A. Wringing fit
B. Loose fit
C. Free fit
D. Snug fit
E. Shrink fit
Answer» F.
432.

Small steel balls are manufactured by

A. Cold heading
B. Casting
C. Rolling
D. Turning in lathe
E. Spinning
Answer» B. Casting
433.

The curve traced by a point on a line as the line rolls on another curve is known as

A. Cycloid
B. Involute
C. Hypocycloid
D. Hyperbola
E. Epicycloid
Answer» C. Hypocycloid
434.

If during operation of a boiler one of the riveted joints is found leaking

A. The boiler is stopped immediately
B. All the riveted joints are reopened and gain riveted
C. Depending upon the zone of boiler in which the joint leaks, decision is taken
D. The joint is repaired if in low pressure zones otherwise boiler sent for repairs
E. None of the above
Answer» E. None of the above
435.

Bolts in structures are often tightened

A. upto 90% of yield point
B. below yield point
C. Increasing the diameter of threaded portion
D. upto breaking point
E. upto or beyond yield point
Answer» F.
436.

In case of spur gears the higher pressure angle results in

A. Wider base and stronger teeth
B. Weaker teeth
C. Narrow base and weaker teeth
D. Non-uniform motion transmission
E. Begger size of gear
Answer» B. Weaker teeth
437.

In case of rivets, the countersunk heads are used to

A. connect unequal sections
B. Increasing the diameter of threaded portion
C. provide a fluish surface
D. connect structural members
E. connect different materials
Answer» D. connect structural members
438.

Which of the following key permits axial relative motion between the shaft and the hub?

A. Wood ruff key
B. Square key
C. Increasing the diameter of threaded portion
D. Gib headed key
E. Feather key
Answer» F.
439.

In order to avoid interference for 20 pressure and teeth, minimum number of teeth should be

A. 8
B. More than 18
C. 12
D. More than 24
E. 16
Answer» C. 12
440.

The bursting pressure of 12 mm ID, 14 mm OD seamless cartridge brass tubing having ultimate whear stress of 225 Mpa, will be nearly

A. 40 Kpa
B. Increasing the diameter of threaded portion
C. 20 Kpa
D. 10 Kpa
E. 30 Kpa
Answer» B. Increasing the diameter of threaded portion
441.

Splined shafts are commonly used in

A. Machine tools
B. Bicycles
C. Aircraft
D. Automobiles
E. None of the above
Answer» E. None of the above
442.

Machines screws are

A. Generally provided with head longer than that of a normal screw
B. Headless
C. Provided with slotted head and used with a nut
D. Screws with button-head
E. Screws with rounded head
Answer» B. Headless
443.

Acoustical materials

A. Create sound
B. Create and reflect sound
C. Absorb sound
D. Reflect sound
E. Absorb and reflect sound
Answer» D. Reflect sound
444.

Smooth bearing surface is an essential pre-requisite in case of

A. thin-film lubrication
B. thick film lubrication
C. both film (A) and (B) above
D. none of the above
E. Increasing the diameter of threaded portion
Answer» C. both film (A) and (B) above
445.

The wrist pin of diesel engine is always in

A. Increasing the diameter of threaded portion
B. a tresss free from shear
C. single shear
D. double shear
Answer» F.
446.

A simple supported steel beam when loaded with a force of 100 kg at A is found to deflect 10 mm at B. What force at B would cause a deflection of 2.5 mm at A

A. 10 kg
B. 50 kg
C. 100 kg
D. 400 kg
E. 25 kg
Answer» F.
447.

A unknown weight falls through 1 cm on a collar rigidly attached to the lower end of a vartical bar 3 cm long and 6 cm2 in section. If the maximum instantaneous extension is 2 mm the value of stress would be

A. 1333 kg/cm2
B. 1000 kg/cm2
C. 667 kg/cm2
D. 1500 kg/cm2
E. 500 kg/cm2
Answer» B. 1000 kg/cm2
448.

The function of gear box in an automobile is

A. To provide variable speeds
B. To reduce speed
C. To increase speed
D. To produce torque
E. To increase efficiency
Answer» B. To reduce speed
449.

Fatigue strength of a surface may be increased by

A. Applying concentrated hydrochloric acid on the surface
B. Applying birine on the surface and then washing with cold water
C. Making surface rough
D. Filling the surface
E. Polishing the surface
Answer» F.
450.

Which type of loading should be avoided

A. Cleavage loading
B. Shear loading
C. Tensile loading
D. none of the above
E. Increasing the diameter of threaded portion
Answer» B. Shear loading