Description : Chromium molybdenum steel cannot be welded using __________ welding. (A) Thermit (B) Electrical resistance (C) Oxy-acetylene (D) Any of these
Last Answer : Option B
Description : 99.5% purity oxygen is used in (A) Cutting and welding by oxy-acetylene flame (B) Hospitals for medicinal purposes (C) Gas masks and artificial breathing apparatus (D) All (A), (B), and (C)
Last Answer : (D) All (A), (B), and (C)
Description : While the oxy-acetylene flame produces a temperature of 3200°C, the temperature produced by oxy-hydrogen flame is about __________ °C. (A) 1800 (B) 2000 (C) 2400 (D) 3000
Last Answer : (B) 2000
Description : Metal cutting by oxy-acetylene flame is accomplished by the __________ of the metal. (A) Burning (B) Intensive oxidation (C) Evaporation (D) None of these
Description : Theoretical volume of oxygen required for complete combustion of 1Nm3 of acetylene, in oxy-acetylene welding is __________ Nm3. (A) 0.5 (B) 1 (C) 1/3 (D) 2.5
Last Answer : Option D
Description : The temperature of oxy-acetylene flame is around (1) 2800°C (2) 3200°C (3) 4000°C (4) 1500°C
Last Answer : 3200°C
Description : Rails in the field are generally welded by using a) Thermit welding b) Gas welding c) Electric arc welding d) Forge welding
Last Answer : a) Thermit welding
Description : Describe in brief the equipments required for oxy-acetylene welding.
Last Answer : The following equipments are required for oxy-acetylene welding. 1. Welding torch or Blowpipe: It is the tool for mixing two gases in the desired volumes and burning the mixture at the end of a ... particularly when the oxides of the base metal have a higher melting point than the metal itself.
Description : List types of welding flames used in Oxy-acetylene welding. Write their characteristics and applications.
Last Answer : Types of Flames: Characteristics Applications. 1)Neutral Flame: When oxygen and acetylene are supplied to the torch in nearly equal volumes, a neutral flame is produced. It has two ... cone of whitish colour. 3) Bluish outer cone High Carbon Steel, non - ferrous alloys,
Description : Which of the following mainly decides the current to be employed is arc welding? (A) Electrode size (B) Plate thickness (C) Voltage across the arc (D) Welded portion length
Last Answer : (A) Electrode size
Description : Which of the following has the highest theoretical flame temperature? (A) Blast furnace gas (B) Hydrogen (C) Acetylene (D) Coke oven gas
Last Answer : (C) Acetylene
Description : Cold cracking in the heat affected zone of a high strength steel weld can take place because of the (A) Retained austenite (B) Martensite formation (C) Relatively high sulphur content in the base metal (D) Sufficient hydrogen present in the welding arc
Last Answer : (B) Martensite formation
Description : Steel is welded using the __________ flame. (A) Carburising (B) Neutral (C) Oxidising (D) All (A), (B) & (C)
Description : 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
Last Answer : c) Oxygen-Hydrogen or Oxygen-Acetylene
Description : Which of the following uses a flat characteristic? a) MAG (GMAW) b) Oxy-fuel gas welding c) Resistance spot welding d) SAW using greater than 1000 amps
Last Answer : a) MAG (GMAW)
Description : Stainless steel is welded with difficulty because of (A) Its high melting temperature (B) Chances of cracking (C) Oxide film formation (D) Chromium carbide formation
Last Answer : Option C
Description : Pick out the wrong statement. (A) Seam welding, projection welding & spot welding are the classification of electrical resistance welding (B) Electrode tip in spot welding is of copper and the ... joined are overlapped and placed between two electrodes (D) Mild steel sheet cannot be spot welded
Last Answer : (D) Mild steel sheet cannot be spot welded
Description : Oxygen cylinders used for autogenous (cutting/welding) purposes are (A) Seamless & made of steel (B) Heat treated before use (C) Made by sand casting (D) Welded steel cylinders
Last Answer : Option A
Description : A butt weld has been made by MMA in a 50mm thick impact tested steel plate. The welding electrode used was a basic type, 5mm diameter. The measured welding parameters for one of the runs was 250 amps, 24 volts, using DC ... given to calculate the arc energy b) 1.9 kJ/mm c) 1.87 kJ/mm d) 2.0 kJ/mm
Last Answer : d) 2.0 kJ/mm
Description : Pick out the wrong statement. (A) Strongly caking coal should not be used in the Lurgi gasifier (B) Acetylene gas cannot be used for illumination purpose (C) Water gas is called blue gas ... is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels
Last Answer : (B) Acetylene gas cannot be used for illumination purpose
Description : Oxyacetylene reducing flame is used while carrying out welding on (A) Alloy steel (B) Grey cast iron (C) Mild steel (D) High carbon steel
Last Answer : (C) Mild steel
Description : The maximum thickness of the metal which can be welded using ultrasonic welding is __________ mm. (A) 0.5 (B) 3 (C) 10 (D) 25
Last Answer : (B) 3
Description : Material of construction of the electrode used in the electric resistance welding is (A) Stainless steel (B) Graphite (C) Copper (D) Steel
Description : Acetylene is commonly used in a gas welding torch. Give the molecular formula for acetylene.
Last Answer : ANSWER: C2H2 or HC2H or H2C2
Description : Consumable electrodes are used in the __________ welding. (A) Gas (B) Arc (C) Thermit (D) Resistance
Last Answer : (B) Arc
Description : Elimination of brittleness resulting from welding of saw blades is done by __________ of the welded portion. (A) Annealing (B) Toughening (C) Work hardening (D) Tempering
Last Answer : (A) Annealing
Description : Motor starter or controller contacts may become welded together if the contacts _____________. A. open too quickly and arc B. close under excessive pressure C. open or close too quickly D. close under excessive starting current
Last Answer : Answer: D
Description : Motor controller or starter contacts may become pitted and welded together if the contacts _____________. A. open under loaded conditions B. close slowly with light pressure C. open too quickly and arc D. close quickly with proportionate pressure
Last Answer : Answer: B
Description : The widest explosive limit is of __________, thereby making it the most explosive gas. (A) Acetylene (B) Petrol vapor (C) Hydrogen (D) Carbon monoxide
Last Answer : (A) Acetylene
Description : Which of the following gases is having the widest explosion limit (about 2 to 81% gas in gas-air mixture), rendering it the property of the most explosive gas? (A) Hydrogen (B) Acetylene (C) Carbon monoxide (D) Ammonia
Last Answer : (B) Acetylene
Description : Projection welding is (i) Electric arc welding (ii) Gas welding (iii)Spot welding (iv) None
Last Answer : (iv) None
Description : Which type of welding is generally used in automobile sector? a) Electric arc welding b) Electric resistance welding c) Gas welding d) Forge welding
Last Answer : b) Electric resistance welding
Description : 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
Last Answer : b) Electric arc welding
Description : Sketch and label different types of gas welding flames. Also give application of any one flame.
Last Answer : 1) Neutral Flame: - A neutral flame is obtained when equal amounts of oxygen and acetylene are mixed and burnt in a torch. Applications: - stainless steel, cast iron, copper ,mild ... when acetylene is supplied more than oxygen. Applications:-high carbon steel, nonferrous alloy
Description : Acetylene gas holder is made of (A) Copper (B) Cast iron (C) Steel (D) Monel metal
Last Answer : (C) Steel
Description : Pick up the incorrect statement (A) The cross-sectional area of the welded member is effective (B) A welded joint develops strength of its parent metal (C) Welded joints provide rigidity (D) Welding takes more time than riveting
Last Answer : (D) Welding takes more time than riveting
Description : Rails used for A T Welding shall not normally be welded? (i) 20 years old . (ii) 30 years old (iii) 40 years old (iv) 50 years old*
Last Answer : iv) 50 years old*
Description : Thermit welding is categorised as the __________ welding. (A) Forge (B) Fusion (C) Resistance (D) Arc
Last Answer : (B) Fusion
Description : Projection welding & stud welding is categorised as the __________ welding. (A) Pressure (B) Thermit (C) Resistance (D) Arc
Last Answer : C) Resistance
Description : Coating provided on the electrodes used in the arc welding is not expected to (A) Add alloying elements (B) Prevent electrode from contamination (C) Stabilise the arc (D) Provide protective atmosphere to weld
Last Answer : (B) Prevent electrode from contamination
Description : Domestic cooking gas consists mostly of (1) methane and ethane (2) liquefied butane and isobutene (3) hydrogen and acetylene (4) ethylene and carbon monoxide
Last Answer : (2) liquefied butane and isobutene Explanation: Domestic gas is another name for Liquefied Petroleum Gas (LPG). Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily ... propane and butane, depending on the season - in winter more propane, in summer more butane.
Description : Domestic cooking gas consists mostly of (1) methane and ethane (2) liquified butane and isobutane (3) hydrogen and acetylene (4) ethylene and carbon monoxide
Last Answer : liquified butane and isobutane
Description : Which of the following is an Inert Gas? (1) Hydrogen (2) Nitrogen (3) Oxygen (4) Argon
Last Answer : (4) Argon Explanation: Argon is an inert gas (noble gas) that is placed in Group 18 of the periodic table. It is the most abundant noble gas in Earth's crust, comprising 20.00015% of the crust. Helium ... (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn) are other noble gases that occur naturally.
Description : When lead-acid batteries are charging, they always give off hydrogen gas that is _____________. A. considered inert B. highly explosive C. extremely toxic D. heavier than air
Description : In the blast furnace, incorporation of water vapour in the blast gives the following effect. (A) Increases the reducing potential of the gas (B) Increases the flame temperature (C) No significant change occurs (D) Increases the hydrogen content in the metal
Last Answer : (A) Increases the reducing potential of the gas
Description : __________ has the widest inflammability limit (explosion limit) of all the gases. (A) Hydrogen (B) Carbon monoxide (C) Acetylene (D) Methane
Description : Argon is used in arc welding because
Last Answer : Argon is used in arc welding because A. low reactivity with metal B. ability to lower the ... of metal C. flammability D. high calorific value
Description : What type of arc welding equipment is necessary when participating in arc welding?
Last Answer : The most important equipment you can have is your safety equipment, your gloves, visor and heavy-duty clothing. You have to have some sort of a power source to generate the electricity necessary for arc welding, so I'd say a power source is your most important arc welding equipment.
Description : In arc welding, Argon is used because of its - (1) Low reactivity with metal (2) Ability to lower the melting point of the metal (3) High flammability (4) High calorific value
Last Answer : (1) Low reactivity with metal Explanation: In arc welding, Argon is used as a shielding gas because it is chemically inert and forms no compounds. At the high temperatures that welding requires, the ... to brittle welds and instability in the welding arc. So,argon and other inert gases are sprayed.