Machine Design Objective Questions and Answers - Set 23 - ObjectiveBooks

# Practice Test: Question Set - 23

1. When two non-intersecting and non-coplanar shafts are connected by gears, the arrangement is known as
(A) Spur gearing
(B) Helical gearing
(C) Bevel gearing
(D) Spiral gearing

2. The ratio of driving tensions in V-belt drives is __________ flat belt drives.
(A) Equal to
(B) sin α times more than
(C) sin α times less than
(D) cosec α times more than

3. The temperature required for full annealing in hypereutectoid steel is
(A) 50°C above upper critical temperature
(B) 50°C below upper critical temperature
(C) 50°C above lower critical temperature
(D) 50°C below lower critical temperature

4. A screw is said to be over hauling screw, if the
(A) Friction angle is less than helix angle
(B) Friction angle is more than helix angle
(C) Friction angle is equal to helix angle
(D) Efficiency of screw is 100%

5. In case of thick cylinders, the tangential stress across the thickness of cylinder is
(A) Maximum at the outer surface and minimum at the inner surface
(B) Maximum at the inner surface and minimum at the outer surface
(C) Maximum at the inner surface and zero at the outer surface
(D) Maximum at the outer surface and zero at the inner surface

6. In a partial journal bearing, the angle of contact of the bearing with the journal is
(A) 120°
(B) 180°
(C) 270°
(D) 360°

7. In a band and block brake, the ratio of tensions on the tight and slack sides of band is given by (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)
(A) T₁/T₂ = μθ × n
(B) T₁/T₂ = (μθ)n
(C) T₁/T₂ = [(1 - μ tanθ)/ (1 + μ tanθ)]n
(D) T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n

8. In a flat belt drive, if the slip between the driver and belt is 1 %, between the belt and follower is 3% and driver and follower pulley diameters are equal, then velocity ratio of the drive will be
(A) 0.96
(B) 0.97
(C) 0.98
(D) 0.99

9. The allowable static stress for steel gears is approximately __________ of the ultimate tensile stress.
(A) One-fourth
(B) One-third
(C) One-half
(D) Double

10. Rankine's theory is used for
(A) Brittle materials
(B) Ductile materials
(C) Elastic materials
(D) Plastic materials

11. Wire ropes as compared to cotton ropes
(A) Are lighter in weight
(B) Offer silent operation
(D) All of these

12. A connecting rod subjected to an axial load may buckle with
(A) X-axis as neutral axis
(B) Y-axis as neutral axis
(C) X-axis or Y-axis as neutral axis
(D) Z-axis

13. Two shafts A and B are made of the same material. The diameter of shaft A is twice as that of shaft B. The power transmitted by the shaft A will be __________ of shaft B.
(A) Twice
(B) Four times
(C) Eight times
(D) Sixteen times

14. The material commonly used for machine tool bodies is
(A) Mild steel
(B) Aluminium
(C) Brass
(D) Cast iron

15. For longitudinal joint in boilers, the type of joint used is
(A) Butt joint with single cover plate
(B) Butt joint with double cover plate
(C) Lap joint with one ring overlapping the other
(D) Any one of the above

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