Design of Steel Structures Multiple Choice Questions on “Types and Properties of Welding”.
1. Arrange the following welds in ascending order as per their usage in structural engineering applications.
a) fillet weld, groove weld, slot and plug weld
b) slot and plug weld, groove weld, fillet weld
c) groove weld, fillet weld, slot and plug weld
d) fillet weld, slot and plug weld, groove weld
Answer: b
Clarification: Fillet welds are used extensively (about 80%) followed by groove welds (15%). Slot and plug welds are rarely used (less than 5%) in structural engineering applications.
2. Which of the following type of weld is most suitable for lap and T-joints?
a) Fillet weld
b) Groove weld
c) Slot weld
d) Plug weld
Answer: a
Clarification: Fillet welds are suitable for lap and T-joints and groove welds are suitable for butt, corner, and edge joints.
3. Which of the following is true about back-up strip provided at bottom of single-V grooves?
a) Back-up strips are commonly used when welding is done from both the sides
b) Back-up strips are commonly used when root opening is sufficient
c) It creates a problem of burn-through
d) It introduces a crevice into the weld geometry
Answer: d
Clarification: Back-up strip is provided at the bottom of single-V/bevel/J or U grooves. It is commonly provided when welding is done from one side or when the root opening is excessive. It introduces a crevice into the weld geometry and prevents the problem of burn-through.
4. The size of root gap and root face for groove weld does not depend on :
a) type of welding process
b) welding position
c) type of metal plate
d) volume of deposited material
Answer: c
Clarification: For groove weld, the root opening or gap is provided for the electrode to access the base of the joint. The size of root gap and root face depends on the following : (i) type of welding process, (ii) welding position, (iii) volume of deposited material, (iv)cost of preparing edges, (v)access for arc and electrode, (vi)shrinkage and distortion.
5. Which of the following groove weld is used for plates of thickness more than 40mm?
a) Double-bevel
b) Single-J
c) Single-U
d) Double-U
Answer: d
Clarification: The groove is made of double-bevel or double-V for plates of thickness more than 12mm, and made of double-U or double-J for plates of thickness more than 40mm. For plates of thickness between 12-40mm, single-J and single-U grooves may be used.
6. Groove welds should have ________ strength as member they join.
a) same
b) less
c) greater
d) half
Answer: a
Clarification: Groove welds will transmit full load of the members they join, so they should have the same strength as the members they join.
7. Which of the following is not true regarding fillet welds?
a) They require less precision in fitting up two sections
b) They are adopted in field as well as shop welding
c) They are assumed to fail in tension
d) They are cheaper than groove welds
Answer: c
Clarification: Fillet welds require less precision in fitting up two sections. They are adopted in field as well as shop welding. They are assumed to fail in shear and are cheaper than groove welds.
8. Which of the following is true about slot and plug welds?
a) They are extensively used in steel construction
b) They are assumed to fail in shear
c) The inspection of these welds is easy
d) They are normally used to connect members carrying tensile loads
Answer: b
Clarification: Slot and plug welds are not extensively used in steel construction. They are used to fill up holes in connections. They are assumed to fail in shear. The inspection of these welds is difficult. They are useful in preventing overlapping parts from buckling.
9. Choose the correct option regarding weld metal.
a) Weld metal is same as parent metal
b) Weld metal is same as steel
c) It has higher yield to ultimate ratio
d) It has higher ductility compared to structural steel
Answer: c
Clarification: Weld metal is a mixture of parent metal and steel melted from electrode. The solidified weld metal has properties characteristic of cast steel. It has higher yield to ultimate ratio but lower ductility compared to structural steel.
10. Which of the following is not true regarding pre-heating of heat affected zone ?
a) Pre-heating does not help to reduce heat affected zone cracks
b) Pre-heating increases the cost of welding
c) It is done to remove surface moisture in highly humid conditions
d) It is done to disperse hydrogen away from weld pool and heat affected zone
Answer: a
Clarification: Pre-heating of joints help to reduce heat affected zone cracks but increases the cost of welding. It is done to remove surface moisture in highly humid conditions, to disperse hydrogen away from weld pool and heat affected zone, to bring steel to ambient temperature in cold climates.