1. direct current with reverse polarity(DCRP) is used
2. direct current with straight polarity(DCSP) is used
3. direct current with straight polarity(DCSP)
4. A.C. is used
5. all of the above used
direct current with straight polarity(DCSP)
1. DCRP
2. DCSP
3. A.C.
4. none of these
DCSP
1. DCRP
2. DCSP
3. A.C.
4. none of these
DCRP
1. gas welding
2. thermit welding
3. forge welding
4. resistance welding
thermit welding
1. arc welding
2. thermit welding
3. gas welding
4. TIG welding
thermit welding
1. chemical reaction involving finely divided aluminium and iron oxide
2. combustion of gases
3. electric arc
4. none of these.
chemical reaction involving finely divided aluminium and iron oxide
1. aluminium and iron oxide
2. aluminium and charcoal
3. iron oxide and charcoal
4. none of these
aluminium and iron oxide
1. 1:1
2. 1:3
3. 3:1
4. 2:1
1:3
1. joining rails, truck frames and broken motor castings
2. repairing broken shears
3. replacing broken gear teeth
4. all of these
all of these
1. weld cools uniformly
2. all part of the weld section are molten at the same time
3. problem with internal residual stresses is minimum
4. all of these
all of these