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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 | |