[I] Choose Correct Answers
1. In gas welding process the gas is
(a) acetylene (b) hydrogen (c) both (a) and (b) (d) none of these.
2. Inert gas used for metal inert gas welding is
(a) NO2 (b) H2S (c) CO2 (d) CO
3. In AC welding
(a) carbon arc is possible (b) carbon arc is not possible
(c) both (a) and (b) (d) none of these.
4. Brazing process is
(a) 450*C to 500*C (b) 400*C to 600*C
(c) 200*C to 250*C (d) 250*C to 300*C
5. Welding produces
(a) Temporary joint (b) Permanent joint
(c) Semi-permanent joint (d) None of these
6. Gas welding is an example of
(a) Pressure welding (b) Resistance welding
(c) Fusion welding (d) None of these
7. Temperature achieved in a gas welding process is around
(a) 150*C (b) 2500*C (c) 3250*C (d) 5000*C
8. A carburizing flame has
(a) An excess of acetylene as compared to oxygen
(b) An excess of CO2 as compared to oxygen.
(c) An excess of oxygen as compared to acetylene
(d) None of these.
9. In an electric resistance welding process
(a) Both heat and pressure is required (b) Only heat required
(c) Only pressure is required (d) None of these
10. To soldering process which combination is used
(a) Lead and Zinc (b) Tin and Zinc
(c) Lead and Tin (d) Copper and Tin
11. Welding torch is an essential equipment used in
(a) Arc welding (b) Resistance welding
(c) Gas welding (d) All of these
12. In resistance welding the time period during which current flows to rise the temperature is:
(a) Weld time (b) On time (c) Off time (d) Squeeze time
13. In carburizing flame the maximum temperature produced is:
(a) about 3200*C (b) about 3500*C (c) about 3000*C (d) None of the above
[II] Fill in the Blanks
14. HAZ stands for ...................
15. Temperature has reached in gas welding is around ...................
16. In carbon arc welding, the work piece being welded is used as ................... electrode and rod of carbon as ................... electrode.
17. AC welding used in ...................
18. OFGW stands for ...................
19. Cylinder used for storing Acetylene gas is first filled with ...... (2010-11)
20. Solder is an alloy of Tin and ............... (2010-11)
[III] True or False Statements
21. A neutral flame is used to weld carbon steels, cast iron, copper, aluminum etc.
22. In leftward or forward welding, the welding rod is held in the left hand at 30-40 oC.
23. Resistance welding does not need flux, filler metal and shielding gas.
24. Argon, helium, CO2 can be used as shielding gas.
25. Bare electrodes can be used in AC arc welding.
26. Reverse polarity is used in carbon arc welding process.
1. (c) 2. (c) 3. (b) 4. (a) 5. (b) 6. (c)
7. (c) 8. (a) 9. (a) 10. (c) 11. (c) 12. (b) 13. (a)
14. heat affected zone 15. 32500C 16. positive, negative
17. Flat position 18. oxy fuel gas welding
19. porons mass, soaked in acetone. 20. lead.
21. (T) 22. (T) 23. (T) 24. (T) 25. (F)
26. (F)
