Machine design objective questions with answers part3

Q1. The shear plane in case of bolts should
(A) be across threaded portion of shank
(B) be parallel to axis of bolt
(C) be normal to threaded portion of shank
(D) never be across the threaded portion

Q2. Castle nut is a locking device in which
(A) one smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
(B) a slot is cut partly is middle of nut and then slot reduced by tightening a screw
(C) a hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
(D) through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end

Q3. When a nut is tightened by plaping a washer below it, the bolt will be subjected to following type of loads
(A) compression
(B) tension
(C) shear
(D) combined loads

Q4. Gear box is used
(A) to produce torque
(B) for speed reduction
(C) to obtain variable speeds
(D) to increase efficiency of system

Q5. The edges of the plates for cylindrical vessels are usually bevelled to an angle of 80° for
(A) reducing stress concentration
(B) ease of manufacture
(C) safety
(D) fullering and caulking

Q6. The piston rod of a steam engine is usually connected to the crosshead by means of
(A) bolted joint
(B) cotter joint
(C) universal joint
(D) universal coupling

Q7. Which of the following pipe joints would be suitable for pipes carrying steam
(A) flanged
(B) threaded
(C) bell and spigot
(D) expansion

Q8. Spring index is
(A) ratio of coil diameter to wire diameter
(B) load required to produce unit deflection
(C) its capability of storing energy
(D) indication of quality of spring

Q9. The shearing stresses in the inner face as compared to outer face of the wire in a heavy close coiled spring is
(A) larger
(B) smaller
(C) equal
(D) larger/smaller depending on diameter of spring coil

Q10. Form coefficient of spring is
(A) ratio of coil diameter to wire diameter
(B) load required to produce unit deflection
(C) its capability of storing energy
(D) concerned With strength of wire of spring

Q11. The ultimate strength of steel in tension in comparison to shear is in the ratio of
(A) 01:01:00
(B) 02:01:00
(C) 03:02:00
(D) 02:03:00

Q12. The permissible stress for carbon steel under static loading is generally taken as
(A) 2000-3000 kg/pm2
(B) 3000-4000 kg/cm2
(C) 4000-4500 kg/cm2
(D) 2500-10,000 kg/cm2

Q13. The property of a material which enables it to resist fracture due to high impact loads is known as
(A) elasticity
(B) endurance
(C) strength
(D) toughness

Q14. A hot short metal is
(A) brittle when cold
(B) brittle when hot
(C) brittle under all conditions
(D) ductile at high temperature

Q15. Guest’s theory of failure is applicable for following type of materials
(A) brittle
(B) ductile
(C) elastic
(D) plastic

Q16. Rankine’s theory of failure is applicable for following type of materials
(A) brittle
(B) ductile
(C) elastic
(D) plastic

Q17. Tensile strength of a mild steel specimen can be roughly predicted from following hardness test
(A) Brinell
(B) Rockwell
(C) Vicker
(D) Shore’s sceleroscope

Q18. Resilience of a material is important, when it is subjected to
(A) combined loading
(B) thermal stresses
(C) wear and tear
(D) shock loading

Q19. In the case of an elastic bar fixed at upper end and loaded by a falling weight at lower end, the shock load produced can be decreased by
(A) decreasing the cross-section area of’ bar
(B) increasing the cross-section area of bar
(C) remain unaffected with cross-section area
(D) would depend upon other factors

Q20. Other method of reducing shock load in the above case can be
(A) to decrease length
(B) to increase length
(C) unaffected by length
(D) other factors would decide same