On This Page
This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on Machine Design Set 1
Q1 | The type of cam used for low and moderate speed engines is generally
- Involute
- Harmonic
- Flat
- Cylindrical
- Tangent
Q2 | Which material is expected to be the hardest?
- Brass
- Copper-zinc
- Molybdenum
- Silver
- Aluminium
Q3 | If machine number is loaded in such a way that the three principla stresses at a point are 600 kg/cm2 compression. 800 kg/cm2 tension and zero. The maximum shear stress at the point will be
- 700 kg/cm2
- 600 kg/cm2
- 1000 kg/cm2
- 800 kg/cm2
- 200 kg/cm2
Q4 | For minimum noise use which type of gears are used
- Bevel gears
- Hypoid gears
- Helical gears
- Cast steel
- Spur gears
Q5 | In cross or regular lay ropes
- The direction of twist in wires in strands is opposite to the direction of twist of strands
- The direction of twist in wires in strands is the same as the direction of twist of strands
- Wires in two adjacent strands are twisted in opposite direction
- Wires are never twisted
- Only one wire is twisted and wrapped around
Q6 | In case of sunk key
- The key way is helical along the shaft
- The key way is cut in bub only
- The key way is cut in both shaft and hub
- The key way is cut in shaft only
- The key is in two parts
Q7 | The included angle of American National threads is
- 55?
- 50?
- 29?
- 47
- 60?
Q8 | Which of the following statement is false?
- Ball and roller bearings are anti-friction bearings
- The sleeve of a muff coupling is designed as a solid shaft
- In designing gear, the tooth is considered as a cantilever subjected to an end load
- Buttress threads are used to transmit power in one direction only
- Increasing the diameter of threaded portion
Q9 | Miter gears are
- Spur gears with same number of teeth
- Gears with different profiles
- Helical gears with same number of teeth
- Stepped spur gears
- Right angled bevel gears with same number of teeth
Q10 | Operation of helical gears is silent and quiet while the operation of the spur gears is noisy because
- helical gears have some helix angle but the spur gears are straight
- there is end thrust in helical gears
- in helical gears, contact begins at one end of the entering tooth and gradually extends along a diagonal line across the tooth face as the gears rotate
- none of the above
- Cast steel
Q11 | In the case of roller bearings the contacting areas between rollers and running tracks are
- Cast steel
- oblong
- parabolic
- elliptical
- circular
Q12 | In door shutters, the type of the spring used is
- spiral spring
- helical torsion spring
- Cast steel
- close coiled helical spring
- conical helical spring
Q13 | A foundation bolt with a circular end is secured to the floor by means of a steel cotter. If the pull on the bolt is 14000 kg, the diameter of the bolt should be
- Double shear
- 50 mm
- 10 mm
- 30 mm
- 20 mm
Q14 | The average values of modulus of rigidity for aluminium brass, copper and steel in descending order is
- Aluminium, nickel, brass, copper and steel
- Aluminium, copper, nickel, brass and steel
- Aluminium, copper, brass, nickel and steel
- Aluminium, brass, copper, nickel and steel
- Aluminium, brass, nickel, copper and steel
Q15 | In a ball bearing steel balls are made of
- Carbon steel
- Stainless steel
- Cast iron
- Carbon chrome steel
- Brass
Q16 | In most machine members, the damping capacity of the material should be
- Anything
- Zero
- High
- Around zero
- Low
Q17 | The loading on a pinion gear is usually
- Compression
- Tension
- Shear
- Cyclic loading
- None of the above
Q18 | St, Venant's theory for failure of material is based on
- maximum shear stress
- maximum strain energy
- maximum tensile stress
- none of the above
- Increasing the diameter of threaded portion
Q19 | The critical speed of a shaft is affected by
- Diameter of the disc
- Eccentricity
- Span of the shaft
- All of the above
- None of the above
Q20 | A thin cylinder contains fluid at a pressure of 30 kg kg/cm2, the internal diameter of the shell is 60 cm and the tensile stress in the material is to be limited to 900 kg/cm2. The shell must have a minimum wall thickness of
- 10 mm
- 9 mm
- 1 mm
- 27 mm
- 12 mm
Q21 | Stub tooth
- Has a profile which is involutic at the base and cycloidal at the top
- Has a profile which is cycloidal at the base and involutic at the top
- Is provided on racks only
- Has a profile shorter than the standard tooth
- Has a profile longer than the standard tooth
Q22 | Approximate horse power that can be transmitted by a shaft 60 mm diameter at 180 r.p.m. with permissible shear stress of 850 kg/cm2, would be
- 35-50
- 85-95
- 30-35
- 50-65
- 65-85
Q23 | The differential equation 10x + 9 x + 810x = 0 describes a one degree of freedom system. The natural frequency of the system is
- 90 cycles per second
- 9 cycles per second
- 10 cycles per second
- 90 sycles per second
- 9 radians per second
Q24 | The concentric helical springs are wound in opposite direction
- to maintain identical shear stress in the two springs
- Increasing the diameter of threaded portion
- to maintain identical stiffness in both springs
- to avoid unequal deflection in the two springs
- to avoid binding of adjacent coils
Q25 | The rivet diameter should be
- More than plate thickness
- Less than the plate thickness
- Equal to the plate thickness
- Equal to the strap thickness
- Half the plate thickness