Practice Test: Question Set - 17
1. The ratio of driving tensions for flat belts, neglecting centrifugal tension, is (where T₁, and T₂ = Tensions on the tight and slack sides of belt respectively, μ = Coefficient of friction, between the belt and pulley, and θ = Angle of contact)
- (A) T₁/T₂
= μθ
- (B) log (T₁/T₂) = μθ
- (C) T₁/T₂
=eμθ
- (D) T₁/T₂
= log μθ
2. If the centre distance of the mating gears having involute teeth is increased, then the pressure angle
- (A) Increases
- (B) Decreases
- (C) Remains
unchanged
- (D) None of
these
3. 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
4. According to Indian standard specifications, a Grey cast iron designated by 'FG 200' means that the
- (A) Carbon
content is 2%
- (B) Maximum
compressive strength is 200 N/mm²
- (C) Minimum
tensile strength is 200 N/mm²
- (D) Maximum
shear strength is 200 N/mm²
5. A bolt is designed on the basis of __________ with a large factor of safety.
- (A) Direct
tensile stress
- (B) Direct
compressive stress
- (C) Direct
bending stress
- (D) Direct shear
stress
6. While designing a screw in a screw jack against buckling failure, the end conditions for the screw are taken as
- (A) Both the
ends fixed
- (B) Both
the ends hinged
- (C) One end
fixed and the other end hinged
- (D) One
end fixed and the other end free
7. In a butt welded joint, the size of weld is __________ the throat of weld.
- (A) 0.5 times
- (B) Equal to
- (C) 2 times
- (D) Double
8. According to I.B.R., when the thickness of the boiler shell (t) is less than 8 mm, then the diameter of the rivet hole (d) is obtained by
- (A) Equating
tearing resistance of the plate to the shearing resistance of the rivets
- (B) Equating
tearing resistance of the plate to the crushing resistance of the rivets
- (C) Equating
shearing resistance to the crushing resistance of the rivets
- (D) None
of the above
9. A feather key is generally
- (A) Loose in
shaft and tight in hub
- (B) Tight in
shaft and loose in hub
- (C) Tight in
both shaft and hub
- (D) Loose
in both shaft and hub
10. The process which improves the machinability of steels, but lowers the hardness and tensile strength is
- (A) Normalising
- (B) Full
annealing
- (C) Process
annealing
- (D) Spheroidising
11. The acme threads are usually found on
- (A) Spindles
of bench vices
- (B) Railway
carriage couplings
- (C) Feed
mechanism of machine tools
- (D) Screw
cutting lathes
12. A double fillet welded joint with parallel fillet weld of length ‘l’ and leg ‘s’ is subjected to a tensile force ‘P’. Assuming uniform stress distribution, the shear stress in the weld is given by
- (A) √2P/s.l
- (B) P/2.s.l
- (C) P/√2.s.l
- (D) 2P/s.l
13. The included angle for the V-belt is usually
- (A) 10°-20°
- (B) 30°-40°
- (C) 40°-60°
- (D) 60°-80°
14. The width of the pulley should be __________ width of the belt.
- (A) Equal to
- (B) Less than
- (C) Greater than
- (D) None of
these
15. A key way lowers
- (A) The strength
of the shaft
- (B) The rigidity
of the shaft
- (C) Both the
strength and rigidity of the shaft
- (D) The
ductility of the shaft
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