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.

251.

Shear stress theory is applicable to

A. Brittle materials
B. Ductile materials
C. Plastic materials
D. Visco-elastic materials
E. Elastic materials
Answer» C. Plastic materials
252.

In case the diameter of a shaft is doubled, its torque transmitting capacity will increase by

A. Big ends of connecting rods for I.C. engines
B. 2 times
C. 8 times
D. 16 times
E. 4 times
Answer» D. 16 times
253.

A bench vice is provided with

A. Vee threads
B. BSW threads
C. Buttress threads
D. Acme threads
E. None of the above
Answer» E. None of the above
254.

Wringing fit is common in

A. Automobile wheel rims
B. Ball bearings
C. Roller bearing
D. Piston pins
E. Slip gauges
Answer» D. Piston pins
255.

An involute gear should have minimum of

A. 6 teeth
B. 20 teeth
C. 4 teeth
D. 8 teeth
E. 12 teeth
Answer» E. 12 teeth
256.

The number of degrees of accuracy in case of gears is

A. Ten
B. Twelve
C. Hundred
D. Six
E. One thousand
Answer» C. Hundred
257.

Setscrews are

A. Used on sheet metals only
B. Used to prevent relative motion between parts
C. Small screws
D. Self hreading
E. Headless screws
Answer» C. Small screws
258.

As per Indian Boilers Regulations the type of joint preferred for circumferential joints is

A. Welded joint with cover plate
B. Any of above
C. Welded joint
D. Reveted butt joint
E. Riveted lap joint
Answer» F.
259.

The maximum efficiency of a scres jack provided with square threads and angle of friction 30? will be

A. 47%
B. 41%
C. 25%
D. 33%
E. 55.50%
Answer» E. 55.50%
260.

The coefficient of friction will be least in case of

A. Leather on metal
B. Asbestos on metal in oil
C. Metal on metal
D. Wood on metal
E. Sintered metal on cast iron in oil
Answer» F.
261.

Which threads have better fatigue characteristics?

A. Threads cut by taps
B. Threads cut by rolling
C. Increasing the diameter of threaded portion
D. Threads cut on lathe
Answer» D. Threads cut on lathe
262.

For which of the following gears noise level is low

A. cast iron gears
B. alloys steel gears
C. non metallic gears
D. none of the above
E. Cast steel
Answer» D. none of the above
263.

If the threads on a bolt are right hand the threads on nut will be

A. Right hand with less clearance
B. Right hand withmore clerance
C. Left hand with more clearance
D. Right hand
E. Left hand
Answer» E. Left hand
264.

A pair of straight tooth bevel gears connects a pair of shafts at 90?. The velocity ratio is 3:1. The cone ptich angle of the pinion will be

A. 22.5?
B. 71.6?
C. 30?
D. 18.4?
E. 60?
Answer» E. 60?
265.

The pitch of 24 mm diameter metric threads would be

A. 6 mm
B. 1 mm
C. 2 mm
D. 5 mm
E. 3 mm
Answer» F.
266.

Which type of gears are preferred for low noise applications?

A. Spur gears with cycloidal profile
B. Spur gears with involute profile
C. Bevel gears
D. Helical gears
E. Any of the above
Answer» E. Any of the above
267.

What type of gears are provided in a switch gear?

A. Spur gears
B. Helical gear
C. Bevel gears
D. Herringbone gears
E. None of the above
Answer» F.
268.

For very heavy loads which of the following gear tooth profile will be preferred?

A. 20? stub involute profile
B. 14
C. 14
D. 14
E. 20? full depth involute profile
Answer» E. 20? full depth involute profile
269.

Gears preferred for minimum axial thrust are

A. Helical gears
B. Worm gears
C. Hypoid gears
D. Herring bone gears
E. Any of the above
Answer» E. Any of the above
270.

The thickness of a gear tooth is measured

A. Along the pitch circle
B. Along the root circle
C. Along the outer circle
D. Average of the profile
E. None of the above
Answer» B. Along the root circle
271.

Abrasion wear of gear tooth occurs due to

A. Poor lubrication
B. Fatigue
C. Presence of foreign particles
D. Excessive load
E. Any of the above
Answer» D. Excessive load
272.

Maximum principal stress theory for the failure of a material at elastic point, is knowns as

A. Von Mises theory
B. Rankines theory
C. Haig's theory
D. Guest's or Tresca's theory
E. Increasing the diameter of threaded portion
Answer» C. Haig's theory
273.

The gears used for non-intersecting perpendicular shafts are

A. Herringbone gears
B. Helical gears
C. Spur gears
D. Hypoid gears
E. Double helical gears
Answer» E. Double helical gears
274.

The holding power of sunk key is due to the resistance it differs in

A. shear and crushing
B. Cast steel
C. crushing only
D. tension only
E. shear only
Answer» B. Cast steel
275.

For design purpose a spur gear tooth is considered

A. As a cantilever
B. As vital component in analysis
C. As a rough surfacerubbing with another rough surface
D. Proped beam
E. None of the above
Answer» B. As vital component in analysis
276.

Fine thread with 16 mm nominal diameter and 1.5 mm pitch is designed as

A. M 1.5 x 16
B. M 16 x 1.5
C. M 16
D. none of the above
E. Cast steel
Answer» C. M 16
277.

The minor-diameter cross-section of the portion of the screw between the nut and the thrust bearing is subjected to

A. Tension
B. Compression
C. Shear
D. Torque
E. Biaxial stress
Answer» F.
278.

Which of the following equipment operates at higher speeds as compared to the remaining?

A. Steam turbines
B. Automobiles
C. Diesel engines
D. Machine tools
E. Fram machinery
Answer» B. Automobiles
279.

An automobile gear box has

A. Simple gear train
B. Compound gear train
C. Epicycle gear train
D. Compound epicyclic gear train
E. None of the above
Answer» C. Epicycle gear train
280.

Which steel will have maximum percentage of carbon?

A. 20 Cr 18 Ni 2
B. 15 Cr 65
C. C 14
D. 40 Cr 40
E. C 15
Answer» E. C 15
281.

A Babbitt is

A. A eutcctic of iron and iron phosphide
B. A gadget for measuring volume
C. A measure of magnetic induction produced in a material
D. Antimony bearing lead or tia alloy
E. None of the above
Answer» E. None of the above
282.

Resilience of material should be considered when it is subjected to

A. Fluctuating load
B. Wear and tear
C. Shock loading
D. Any of the above
E. None of the above
Answer» D. Any of the above
283.

A reverted gear train is one in which

A. The direction of rotation of first and last gear is the same
B. The direction of rotation of first and last gear is opposite
C. The first and last gear are on the same shaft
D. The first and the last gear are essentially on separate but parallel shafts
E. None of the above
Answer» D. The first and the last gear are essentially on separate but parallel shafts
284.

While designing a warm and a worm wheel the sign should be governed by

A. Worm
B. Worm wheel
C. Any one of the two
D. Standards designs should be followed
E. None of the above
Answer» B. Worm wheel
285.

Which of the following drive cannot be used for driving cam shaft of a four stroke intemal cambustion engine?

A. Spur gear drive
B. Helical gear drive
C. Chain drive
D. V-belt drive
E. None of the above
Answer» E. None of the above
286.

The maximum thickness of the plates used in pressed steel tanks is

A. Increasing the diameter of threaded portion
B. 3 mm
C. 5 mm
D. 6 mm
E. 4 mm
Answer» D. 6 mm
287.

In case of rolled steel beams, the chear force is resisted by

A. Increasing the diameter of threaded portion
B. flanges only
C. web only
D. web and flanges together
E. top flange only
Answer» D. web and flanges together
288.

Fine scratches assist in librication in

A. thin film lubrication
B. thick film lubrication
C. both (A) and (B) above
D. none of the above
E. Increasing the diameter of threaded portion
Answer» B. thick film lubrication
289.

Screw parts with a right hand thread must only be stressed

A. In the direction of screwing in
B. In the direction of screwing out
C. In the direction normal to the screw axis
D. In the shear plane
E. In the plane of principal axis
Answer» B. In the direction of screwing out
290.

In an open belt-pulley drive the bodily slip occurs

A. first at larger pulley
B. first at smaller pulley
C. simultaneously on both the pulleys
D. none of the above
E. Cast steel
Answer» D. none of the above
291.

The ultimate strength design of steel structures makes use of

A. elastic and plastic analysis of structures
B. Increasing the diameter of threaded portion
C. plastic analysis of structures
D. ultimate analysis
E. elastic analysis of structures
Answer» F.
292.

A starter in automobile is generally

A. Single phase a.c.motor
B. dc shunt motor
C. dc series motor
D. dc compound motor
E. None of the above
Answer» D. dc compound motor
293.

Rivets are

A. Heated before inserting in position
B. Heated after inserting in position
C. Not heated at all
D. Cold forged
E. None of the above
Answer» B. Heated after inserting in position
294.

Flexible shafts are made of

A. thin mild steel rod
B. Increasing the diameter of threaded portion
C. hollow mild steel rod
D. wavy steel wires
Answer» F.
295.

Poisson's ratio for steel is

A. 0.33
B. 0.27
C. 0.1
D. 1
E. None of the above
Answer» C. 0.1
296.

If the stress at elastic limit is Se, then the modulus of resistance is proportional to

A. (Se)
B. (Se)1/2
C. (Se)2
D. Se
E. (Se)2/2
Answer» B. (Se)1/2
297.

If screw threads are to be used in a situation involving high stresses in one direction only, the types of threads suitable for this would be

A. BA
B. BSW
C. Buttress
D. Acme
E. Square
Answer» D. Acme
298.

Stub tooth is

A. Longer than standard tooth depth
B. Non-standard tooth
C. Shorter than standard tooth depth
D. Equivalent rack tooth
E. Standard gear tooth
Answer» D. Equivalent rack tooth
299.

Fatigue is mostly initiated at

A. core
B. centre
C. Increasing the diameter of threaded portion
D. surface
E. core
Answer» E. core
300.

In a horizontal flat belt drive for power transmission it is customary to use

A. bottom side of the belt as slack side
B. top side of the belt as slack side
C. crossed-belting
D. none of the above
E. Cast steel
Answer» C. crossed-belting