991 + Mcqs in Machine Design Page 1 McqOptions

1.	Lewis form factor for composite and full depth involute system is (where T = Number of teeth)
A.	[A].
B.	[B].
C.	[C].
D.	none of these
Answer» B. [B].

Discussion

2.	The Wahl's stress factor (K) for springs is given by (where )
A.	[A].
B.	[B].
C.	[C].
D.	[D].
Answer» E.

Discussion

3.	A shaft is subjected to a maximum bending stress of 80 N/mm2 and maximum shearing stress equal to 30 N/mm2 at a particular section. If the yield point in tension of the material is 280 N/mm2 and the maximum shear stress theory of failure is used, then the factor of safety obtained will be
A.	2.5
B.	2.8
C.	3
D.	3.5
Answer» C. 3

Discussion

4.	If P1 is the initial tension due to tightening up the bolt and P2 is the external load on the bolt, then the resultant load (P) on a bolt may be obtained by using the relation (where a = Ratio of elasticity of connected parts to the elasticity of bolt)
A.	P = P1 + P2
B.	P = P1 - P2
C.	[C].
D.	[D].
Answer» E.

Discussion

5.	The permissible stress in the fillet weld is 100 N/mm2. The fillet weld has equal leg lengths of 15 mm each. The allowable shearing load on the weldment per cm length of the weld is
A.	7.5 kN
B.	10.6 kN
C.	15 kN
D.	22.5 kN
Answer» C. 15 kN

Discussion

6.	A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, The junction radius is 60 mm and the junction pressure is 1.1 N/mm2. The maximum hoop stress developed in the inner cylinder is
A.	3.6 N/mm2 compression
B.	3.6 N/mm2 tension
C.	7.2 N/mm2 compression
D.	7.2 N/mm2 tension
Answer» D. 7.2 N/mm2 tension

Discussion

7.	A metal pipe of 1 m diameter contains a fluid having a pressure of 1 N/mm2. If the permissible tensile stress in the metal is 20 N/mm2, then the thickness of the metal required for making the pipe will be
A.	5 mm
B.	10 mm
C.	15 mm
D.	25 mm
Answer» E.

Discussion

8.	The condition for maximum power transmission is that the maximum tension in the flat belt should be equal to (Where, Pc = tension in belt due to centrifugal force)
A.	Pc
B.	Pc
C.	c/3
D.	Pc
Answer» B. Pc

Discussion

9.	When the belt is transmitting maximum power, the belt speed should be (Where, m = mass of belt per meter (kg/m) and Pmax = maximum permissible tension in belt (N))
A.	(Pmax / 2m)
B.	(Pmax / 3m)
C.	(Pmax / m)
D.	(3m /Pmax)
Answer» C. (Pmax / m)

Discussion

10.	The machine screws are
A.	slotted for a screw driver and are generally used with a nut
B.	similar to tap bolts except that they are of small size and a variety of shapes of heads are available
C.	used to prevent relative motion between the two parts
D.	none of the above
Answer» B. similar to tap bolts except that they are of small size and a variety of shapes of heads are available

Discussion

11.	If the tearing efficiency of a riveted joint is 50%, then the ratio of diameter of rivet to the pitch is
A.	0.20
B.	0.30
C.	0.50
D.	0.70
Answer» D. 0.70

Discussion

12.	The bending moment M and a torque T is applied on a solid circular shaft. If the maximum bending stress equals to maximum shear stress developed, then M is equal to
A.	T/2
B.	T
C.	2 T
D.	4 T
Answer» B. T

Discussion

13.	The working of metals above the recrystallisation temperature is known as hot working.
A.	True
B.	False
C.	Can't say
D.	None of these
Answer» B. False

Discussion

14.	The efficiency of a square threaded screw is maximum if the helix angle is equal to (where φ = Angle of friction)
A.	90° - φ
B.	45° - φ
C.	45° - φ/2
D.	45° + φ/2
Answer» D. 45° + φ/2

Discussion

15.	The velocity factor for precision metallic gears cut with high accuracy and operating at velocities upto 20 m/s is equal to
A.	0.75/ (0.75 + √v)
B.	3/ (3 + v)
C.	4.5/ (4.5 + v)
D.	6/ (6 + v)
Answer» B. 3/ (3 + v)

Discussion

16.	When a cylinder is subjected to a very high internal fluid pressure, the thin cylinder should be used.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

17.	In a steam engine, the piston rod is usually connected to the crosshead by means of a
A.	knuckle joint
B.	cotter joint
C.	oldham coupling
D.	universal joint
Answer» C. oldham coupling

Discussion

18.	The pressure angle for involute gears depends upon the size of teeth.
A.	Agree
B.	Disagree
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

19.	The load placed at the top of the screw in a mechanical screw jack is prevented from rotation by providing a swivelling mechanism.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» B. Incorrect

Discussion

20.	The cam follower extensively used in air-craft engines is
A.	knife edge follower
B.	flat faced follower
C.	spherical faced follower
D.	roller follower
Answer» E.

Discussion

21.	In an ordinary bolt, the effect of the impulsive loads applied axially is concentrated on the cross-sectional area at the root of the threads.
A.	Yes
B.	No
C.	Can't say
D.	None of these
Answer» B. No

Discussion

22.	The edges of the boiler plates are bevelled to an angle of
A.	45°
B.	60°
C.	70°
D.	80°
Answer» E.

Discussion

23.	If the helix angle of a helical gear is increased, the load carrying capacity of the tooth increases.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

24.	Which of the following cotter joint will be used to connect strap end of a connecting rod ?
A.	Spigot and socket cotter joint
B.	Sleeve and cotter joint
C.	Gib and cotter joint
D.	any one of these
Answer» D. any one of these

Discussion

25.	A cotter joint is used to transmit
A.	axial tensile load only
B.	axial compressive load only
C.	combined axial and twisting loads
D.	axial tensile or compressive loads
Answer» E.

Discussion

26.	The property of a bearing material which has the ability to accomodate shaft deflections and bearing inaccuracies by plastic deformation without excessive wear and heating, is known as
A.	bondability
B.	embeddability
C.	comformability
D.	fatigue strength
Answer» D. fatigue strength

Discussion

27.	An aluminium member is designed on the basis of
A.	yield stress
B.	elastic limit stress
C.	proof stress
D.	ultimate stress
Answer» B. elastic limit stress

Discussion

28.	The parallel fillet welded joints are designed for compressive strength.
A.	Agree
B.	Disagree
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

29.	The bolts of smaller diameter than M16 are not permitted in making fluid tight joints.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» B. Incorrect

Discussion

30.	A steel containing more than 0.8% carbon is known as eutectoid steel.
A.	Yes
B.	No
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

31.	The Lewis equation for gear tooth with involute profile predicts the static load capacity of cantilever beam of uniform strength.
A.	True
B.	False
C.	Can't say
D.	None of these
Answer» B. False

Discussion

32.	A shaft is designed on the basis of rigidity and stiffness.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» B. Incorrect

Discussion

33.	Which of the following screw thread is used for power transmission in one direction only.
A.	Acme threads
B.	Square threads
C.	Buttress threads
D.	Multiple threads
Answer» D. Multiple threads

Discussion

34.	A parallel sunk key, made of steel, is equally strong in shearing and crushing.
A.	Yes
B.	No
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

35.	For high speed engines, the cam follower should move with
A.	uniform velocity
B.	simple harmonic motion
C.	uniform accleration and retardation
D.	cycloidal motion
Answer» E.

Discussion

36.	The springs mostly used in machinery have spring index less than 3.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

37.	A flange coupling is a type of rigid coupling.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» B. Incorrect

Discussion

38.	The ratio of pitch circle diameter in millimetres to the number of teeth, is called
A.	circular pitch
B.	diametral pitch
C.	module
D.	none of these
Answer» D. none of these

Discussion

39.	A basic hole is one whose
A.	lower deviation is zero
B.	upper deviation is zero
C.	lower and upper deviations are zero
D.	none of these
Answer» B. upper deviation is zero

Discussion

40.	The steel widely used for motor car crankshafts is
A.	nickel steel
B.	chrome steel
C.	nickel chrome steel
D.	high speed steel
Answer» C. nickel chrome steel

Discussion

41.	In a V-belt drive, the belt makes contact at the bottom of the groove of the pulley.
A.	Agree
B.	Disagree
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

42.	In a sawn nut, a slot is cut about half way through the nut and a small screw is tightened between the nut and the bolt in order to produce more friction.
A.	Agree
B.	Disagree
C.	Can't say
D.	None of these
Answer» B. Disagree

Discussion

43.	In the levers of first type, the mechanical advantage is __________ one.
A.	less than
B.	equal to
C.	more than
D.	None of these
Answer» D. None of these

Discussion

44.	A shoe brake is commonly used in railway trains.
A.	Yes
B.	No
C.	Can't say
D.	None of these
Answer» B. No

Discussion

45.	In a crossed belt drive, the shafts are arranged parallel and rotate in the same directions.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

46.	The velocity factor for carefully cut gears operating at velocities upto __________ is equal to 4.5/4.5 + v.
A.	10 m/s
B.	12.5 m/s
C.	15 m/s
D.	20 m/s
Answer» C. 15 m/s

Discussion

47.	The radial stress across the thickness of a thick cylinder is maximum at the inner surface and zero at the outer surface.
A.	True
B.	False
C.	Can't say
D.	None of these
Answer» B. False

Discussion

48.	When plates are fastened by a rivet, the holes in the plates should be made by punching and reaming.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

49.	The minor diameter of a screw thread is also known as outside or nominal diameter.
A.	Correct
B.	Incorrect
C.	Can't say
D.	None of these
Answer» C. Can't say

Discussion

50.	An open coiled helical compression spring 'A' of mean diameter 50 mm is subjected to an axial load W. Another spring 'B' of mean diameter 25 mm is similar to spring 'A' in all respects. The deflection of spring 'B' will be __________ as compared to spring 'A'.
A.	one-eighth
B.	one-fourth
C.	one-half
D.	double
Answer» B. one-fourth

Discussion

Explore topic-wise MCQs in GATE (Mechanical Engineering).

Lewis form factor for composite and full depth involute system is (where T = Number of teeth)

The Wahl's stress factor (K) for springs is given by (where )

A shaft is subjected to a maximum bending stress of 80 N/mm2 and maximum shearing stress equal to 30 N/mm2 at a particular section. If the yield point in tension of the material is 280 N/mm2 and the maximum shear stress theory of failure is used, then the factor of safety obtained will be

If P1 is the initial tension due to tightening up the bolt and P2 is the external load on the bolt, then the resultant load (P) on a bolt may be obtained by using the relation (where a = Ratio of elasticity of connected parts to the elasticity of bolt)

The permissible stress in the fillet weld is 100 N/mm2. The fillet weld has equal leg lengths of 15 mm each. The allowable shearing load on the weldment per cm length of the weld is

A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, The junction radius is 60 mm and the junction pressure is 1.1 N/mm2. The maximum hoop stress developed in the inner cylinder is

A metal pipe of 1 m diameter contains a fluid having a pressure of 1 N/mm2. If the permissible tensile stress in the metal is 20 N/mm2, then the thickness of the metal required for making the pipe will be

The condition for maximum power transmission is that the maximum tension in the flat belt should be equal to (Where, Pc = tension in belt due to centrifugal force)

When the belt is transmitting maximum power, the belt speed should be (Where, m = mass of belt per meter (kg/m) and Pmax = maximum permissible tension in belt (N))

The machine screws are

If the tearing efficiency of a riveted joint is 50%, then the ratio of diameter of rivet to the pitch is

The bending moment M and a torque T is applied on a solid circular shaft. If the maximum bending stress equals to maximum shear stress developed, then M is equal to

The working of metals above the recrystallisation temperature is known as hot working.

The efficiency of a square threaded screw is maximum if the helix angle is equal to (where φ = Angle of friction)

The velocity factor for precision metallic gears cut with high accuracy and operating at velocities upto 20 m/s is equal to

When a cylinder is subjected to a very high internal fluid pressure, the thin cylinder should be used.

In a steam engine, the piston rod is usually connected to the crosshead by means of a

The pressure angle for involute gears depends upon the size of teeth.

The load placed at the top of the screw in a mechanical screw jack is prevented from rotation by providing a swivelling mechanism.

The cam follower extensively used in air-craft engines is

In an ordinary bolt, the effect of the impulsive loads applied axially is concentrated on the cross-sectional area at the root of the threads.

The edges of the boiler plates are bevelled to an angle of

If the helix angle of a helical gear is increased, the load carrying capacity of the tooth increases.

Which of the following cotter joint will be used to connect strap end of a connecting rod ?

A cotter joint is used to transmit

The property of a bearing material which has the ability to accomodate shaft deflections and bearing inaccuracies by plastic deformation without excessive wear and heating, is known as

An aluminium member is designed on the basis of

The parallel fillet welded joints are designed for compressive strength.

The bolts of smaller diameter than M16 are not permitted in making fluid tight joints.

A steel containing more than 0.8% carbon is known as eutectoid steel.

The Lewis equation for gear tooth with involute profile predicts the static load capacity of cantilever beam of uniform strength.

A shaft is designed on the basis of rigidity and stiffness.

Which of the following screw thread is used for power transmission in one direction only.

A parallel sunk key, made of steel, is equally strong in shearing and crushing.

For high speed engines, the cam follower should move with

The springs mostly used in machinery have spring index less than 3.

A flange coupling is a type of rigid coupling.

The ratio of pitch circle diameter in millimetres to the number of teeth, is called

A basic hole is one whose

The steel widely used for motor car crankshafts is

In a V-belt drive, the belt makes contact at the bottom of the groove of the pulley.

In a sawn nut, a slot is cut about half way through the nut and a small screw is tightened between the nut and the bolt in order to produce more friction.

In the levers of first type, the mechanical advantage is __________ one.

A shoe brake is commonly used in railway trains.

In a crossed belt drive, the shafts are arranged parallel and rotate in the same directions.

The velocity factor for carefully cut gears operating at velocities upto __________ is equal to 4.5/4.5 + v.

The radial stress across the thickness of a thick cylinder is maximum at the inner surface and zero at the outer surface.

When plates are fastened by a rivet, the holes in the plates should be made by punching and reaming.

The minor diameter of a screw thread is also known as outside or nominal diameter.

An open coiled helical compression spring 'A' of mean diameter 50 mm is subjected to an axial load W. Another spring 'B' of mean diameter 25 mm is similar to spring 'A' in all respects. The deflection of spring 'B' will be __________ as compared to spring 'A'.