Tough Manufacturing Engineering Questions on “Resistance Welding”.
1. Which one of the following is the simplest type of resistance welding used in making lap welds?
a) Resistance spot
b) Resistance seam
c) Projection
d) Upset
Answer: a
Clarification: The simplest form of the process is spot welding for lap welds, where the pressure is provided by clamping two or more overlapping sheets between two electrodes. Up to a thickness of 12.7 mm we can go for it.
2. The time required for electrodes to align and clamp the work piece together under them is known as?
a) Hold time
b) Off time
c) Squeeze time
d) Weld time
Answer: c
Clarification: Squeeze time is the time interval between the initial application of the electrode force on the work and first application of current. Squeeze time is necessary to delay the weld current until the electrode force has attained the desired level.
3. Time of current flow through the work piece till they are heated to require temperature is known as?
a) Hold time
b) Off time
c) Squeeze time
d) Weld time
Answer: d
Clarification: Weld time is the time during which welding current is applied to the metal sheets. The weld time is measured and adjusted in cycles in cycles of line voltage as are all timing functions.
4. Time, when pressure is maintained on the molten metal without electric current, is known as?
a) Hold time
b) Off time
c) Squeeze time
d) Weld time
Answer: a
Clarification: Hold time is the period programmed into the weld controller, typically between the end of weld time and the command to open the electrode.
5. The time after which the pressure is released, and metal piece is removed for next cycle is known as?
a) Hold time
b) Off time
c) Squeeze time
d) Weld time
Answer: b
Clarification: Off time is the time after which the pressure is released, and metal piece is removed for next cycle. It begins automatically after hold time.[/
6. The spot formed between the interface of work piece, when strong current and pressure is applied is known as?
a) Joint
b) Nugget
c) Core
d) Tee
Answer: b
Clarification: The spot formed between the interface of work piece when strong current and pressure is applied is known as a nugget. It may be of any shape.
7. In which of the following welding process disc electrodes are used instead of the cylindrical electrode?
a) Resistance spot
b) Resistance seam
c) Projection
d) Upset
Answer: b
Clarification: In resistance seam welding disc electrodes are used instead of the cylindrical electrode. Disc are rotated for the welding operation.
8. In which of the following operation embossing is required before welding?
a) Resistance spot
b) Resistance seam
c) Projection
d) Upset
Answer: c
Clarification: In projection, welding embossing is required before welding. It is non-productive time used in preparation of welding.
9. In which of the following welding operation the pieces are joined by butt joint?
a) Resistance spot
b) Resistance seam
c) Projection
d) Upset
Answer: d
Clarification: Upset welding or resistance butt welding is a welding technique that produces coalescence simultaneously over the entire area of abutting surfaces or progressively along a joint, by the heat obtained from resistance to electric current through the area where those surfaces are in contact.
10. In which of the following operation it is possible to weld more than one spot at a given time?
a) Resistance spot
b) Resistance seam
c) Projection
d) Upset
Answer: c
Clarification: The advantage of projection welding include flexibility, as the welder can weld more than one spot at a time. Additionally, the welder can position welded spots more closely to each other than is possible with spot welding.