Machine Design Multiple Choice Questions on “Welded Joints Basics”.
1. All welding processes require pressure along with heat.
a) Yes
b ) No, fusion doesn’t require
c) Can’t be stated
d) None of the listed
Answer: b
Clarification: Welding processes involving only heat and no pressure are called the fusion welding processes.
2. The capacity of welded structures to damp vibrations is quite good.
a) True
b) False
Answer: b
Clarification: Capacity of welded joints to damp vibrations is poor.
3. Themit consists of a finely divided mixture of iron oxide and copper.
a) True
b) False
Answer: b
Clarification: Thermite is a mixture of iron oxide and copper.
4. Rails in the field are generally welded by using
a) Thermit welding
b) Gas welding
c) Electric arc welding
d) Forge welding
Answer: a
Clarification: Wherever it is uneconomical to carry welding equipments, thermit welding is used.
5. In gas welding which of the following is generally used?
a) Oxygen-Hydrogen
b) Oxygen-Acetylene
c) Oxygen-Hydrogen or Oxygen-Acetylene
d) None of the mentioned
Answer: c
Clarification: Intense heat is released I a controlled way and at a moderate temperature.
6. Among gas and electric arc welding, which has the higher rate of heating?
a) Gas welding
b) Electric arc welding
c) Gas welding and electric arc welding have equal rate of heating
d) Cannot be determined
Answer: b
Clarification: Gas welding has a gas temperature of about 3200’C while arc temperature is about 40000’C.
7. Forge welding involves heating of parts to elastic stage and joint is prepared by impact force.
a) Yes
b) No, it is done up to plastic stage
c) Heating is done up to boiling point
d) None of the listed
Answer: b
Clarification: Heating is done up to plastic stage.
8. Filler material is used in electric resistance welding.
a) Yes
b) No filler material used
c) Depends on the type of welding
d) None of the listed
Answer: b
Clarification: No filler material is used. Only the heat released from resistance of metallic parts to current is used for melting the adjoining parts.
9. Which type of welding is generally used in automobile sector?
a) Electric arc welding
b) Electric resistance welding
c) Gas welding
d) Forge welding
Answer: b
Clarification: Electric resistance welding can be easily automated and hence is used in automobile sector.
10. Hard peening is
a) Hammering the weld across the length while the joint is hot
b) Hammering the weld along the length while the joint is hot
c) Hammering the weld along the length while the joint is cold
d) Hammering the weld across the length while the joint is cold
Answer: b
Clarification: Hammering is doe to relieve stresses and inducing compressive stresses to improve the fatigue strength of the joint.