# 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

Show and hide multiple DIV using JavaScript View All Answers