RRB JE Mechanical- Welding Questionbank 2

Mechanical-Engineering

In a linear arc welding process, the heat input per unit length is inversely proportional to —-? (Konkan Railway SSE 2015) RRB Allahabad JE (09.07.2012)

  • Welding current
  • Welding voltage
  • Welding speed
  • Duty cycle of the power source

Explanation:

  • Heat input per unit length (H) = VI / S, where V = Voltage, I = Current, S = Welding speed. Therefore, heat input is inversely proportional to welding speed.

“Ensure correct joint preparation, correct electrode size and filler rod size and correct travel speed”. We are talking about —-? (RRB SSE Secundarabad Green paper, 21.12.2014)

  • Gas welding
  • Arc welding
  • Thermal welding
  • Seam welding

Explanation:

  • In arc welding, ensuring correct joint preparation, electrode size, filler rod size, and correct travel speed are essential for a good weld.

Electrode gets consumed in the following welding process —-? (RRB Chandigarh SSE 25.10.2009)

  • gas
  • resistance
  • thermit
  • arc

Explanation:

  • Generally in arc welding processes like MIG and MAG welding, the electrode gets consumed. However, in TIG arc welding, the electrode is not consumed. Metal transfer across the arc is due to electromagnetic force, gravity, gas expansion, and surface tension.

The strength of a properly welded joint as compared to base metal would be —-? (RRB Gorakpur RDSO SSE 25.10.2009)

  • same
  • more
  • less
  • unpredictable

Explanation:

  • The strength of a properly welded joint is greater than that of the base metal.

For Welding process, which is NOT correct? (RRB SSE Bilaspur Yellow paper, 21.12.2014)

  • Welding size depends on contact area of the face of Electrodes
  • Metal fusion takes place by raising the temperature to fusion point
  • In Pressure welding the ends of metals pieces are joined in Elastic state
  • Gas flame is used as heat source in gas welding

Explanation:

  • In pressure welding, the metal pieces are joined at the end of the plastic stage, not the elastic state. The other statements are correct.

Which of the following joining processes are best suited for manufacturing pipes to carry gas products? (RRB Allahabad JE 25.10.2009)

  • Riveting
  • Welding
  • Bolts and nuts
  • Riveting and Bolts and nuts

Explanation:

  • Welding is the best method for joining pipes carrying gaseous products because it makes a leak-proof and permanent joint. The strength of a welded joint is also higher compared to riveted or nut-bolt joints.

Welding units operate at what power factor? (RRB Bhopal TM SSE 25.10.2009)

  • 0.3
  • 0.6
  • 0.8
  • 0.9

Explanation:

  • Welding transformers are highly inductive loads, typically having a power factor below 0.5, often around 0.3.

Open circuit voltage for arc welding is of the order of —-? (RRB Bangalore SSE 09.09.2012)

  • 18-40 volts
  • 40-95 volts
  • 100-125 volts
  • 130-170 volts

Explanation:

  • Open circuit voltage for arc welding is generally 40-95V. Arc voltage (during welding) is typically 18-40V.

In Arc welding, the arc length should be approximately equal to —-? (RRB Gorakhpur Design SSE 09.09.2012)

  • one and a half time the diameter of electrode rod
  • twice the diameter of electrode rod
  • half the diameter of the electrode rod
  • diameter of electrode rod

Explanation:

  • In arc welding, the correct arc length is approximately equal to the diameter of the electrode rod. This ensures the voltage and current remain correct.

In arc welding d.c. reverse polarity is used to bear greater advantage in —-? (RRB JE (Shift-3), 29.8.2015)

  • Overhead welding
  • Flat welding of lap joints
  • Edge welding
  • Flat welding of but joints

Explanation:

  • DCRP (Direct Current Reverse Polarity) is advantageous in overhead welding because less heat is generated on the workpiece (connected to the negative terminal), reducing the chance of molten metal dropping due to gravity.

In arc welding operations the current value is decided by —-? (RRB Chandigarh SSE 09.09.2012)

  • thickness of plate
  • length of welded portion
  • voltage across the arc
  • size of the electrode

Explanation:

  • The welding current value is determined by the diameter/size of the electrode.

The welding setup is said to have straight polarity, when —-? RRB JE [Exam Date: 30-08-2015 (Shift-1I)]

  • work is connected to the positive terminal and the electrode holder to the negative terminal
  • work is connected to the negative terminal and the electrode holder to the positive terminal
  • work is connected to the positive terminal and the electrode holder is carried
  • work is connected to the negative terminal and the electrode holder is carried

Explanation:

  • Straight Polarity: Work is connected to the positive terminal and the electrode to the negative terminal. Reversed Polarity: Work is connected to the negative terminal and the electrode to the positive terminal.

In welding copper alloys with TIG arc welding —-? (RRB Bhubneshwar JE II 29.11.2008) RRB JE [Exam Date: 04-01-2015 (Yellow Paper)]

  • direct current with straight polarity is used
  • direct current with reversed polarity is used
  • alternating current is used
  • any one of these

Explanation:

  • For welding copper alloys with TIG welding, DC with straight polarity is used.

Arc blow is a welding defect which is encountered —-? (RRB Bhubneshwar JE-11 19.12.2010)

  • in arc welding using AC current
  • in arc welding using DC current
  • in gas welding
  • in thermit welding

Explanation:

  • Arc blow (unwanted deflection of the arc) is mainly encountered during DC arc welding due to the interaction of magnetic fields around the welding area.

Arc stability is better with —-? RRB SSE [Exam Date: 16-09-2015 (Shift-1I)] (RRB JE (Shift-1I), 16.09.2015)

  • AC welding
  • DC welding
  • Both AC and DC welding
  • Specially designed wave forms

Explanation:

  • Arc stability is better with DC welding because the magnitude and direction of current are constant, making it easier to stabilize. In AC, both change continuously.

Magnetic arc blow is —-? (RRB Allahabad JE 19.12.2010)

  • a recent welding technique
  • used to weld materials
  • occurs when welding near equator
  • phenomenon of occurrence of splatter because of magnetic fields created in d.c. arc welding

Explanation:

  • Magnetic arc blow is a phenomenon of splatter occurrence caused by magnetic fields created in DC arc welding. It is also known as arc wander.

Weaving in arc welding refers to —-? RRB SSE [Exam Date: 03-09-2015 (Shift-1)]

  • side to side motion of electrode at right angles to the direction of the welding
  • side to side motion of the electrode along the direction of the welding
  • spiral motion given to electrode
  • a technique of striking the arc

Explanation:

  • Weaving in arc welding is the side-to-side motion of the electrode at right angles to the welding direction.

Which of the following welding process does not have high deposition rate? (RRB Allahabad SSE 19.12.2010)

  • Shielded metal arc welding
  • Electro slag welding
  • Gas shielded metal arc welding
  • Flux core arc welding

Explanation:

  • Shielded Metal Arc Welding (SMAW) does not have a high deposition rate compared to other processes like Electro Slag Welding, Gas Metal Arc Welding, and Flux Core Arc Welding.

Which of the following true about shielded metal Arc welding? (RRB Allahabad SSE 19.12.2010)

  • Equipment cost is high
  • Cannot weld different type of metals
  • Cannot used for metal sheets under 1.5mm thickness
  • Entire electrode can be used

Explanation:

  • SMAW is unsuitable for metal sheets less than 1.5 mm thick. It has low equipment cost and can weld different metals, but the entire electrode may not be fully used.

Which of the following welding process does not uses the consumable electrode? (RRB Mumbai SSE 05.10.2008)

  • Gas metal arc welding
  • Submerged arc welding
  • Gas tungsten arc welding
  • Both gas metal arc and submerged arc welding

Explanation:

  • Gas Tungsten Arc Welding (GTAW) or TIG welding uses a non-consumable tungsten electrode.

Electrode used in TIG is —-? (DMRC JE 20.04.2018) RRB Kolkata Diesel Je (25.10.2009)

  • Aluminium
  • Cast iron
  • Copper
  • Tungsten

Explanation:

  • TIG welding uses a non-consumable tungsten electrode. The arc is generated between the tungsten electrode and the workpiece.

Which gases are used in TIG welding? (Konkan Railway TA 2017) RRB JE [Exam Date 26.08.2015 (Shift-I)]

  • Helium and Neon
  • Hydrogen and Oxygen
  • Oxygen and Acetylene
  • Argon and Helium

Explanation:

  • In TIG welding, Argon and Helium are used as shielding gases to protect the weld area from atmospheric contamination.

TIG Welding stand for —-? (RRB JE (Shift-1), 27.08.2015)

  • Temperature insulated Gas Welding
  • Tungsten inert gas Welding
  • Thermally induced Gas Welding
  • Tungsten Insulated Gas Welding

Explanation:

  • TIG stands for Tungsten Inert Gas Welding (also known as Gas Tungsten Arc Welding). It uses a non-consumable tungsten electrode.

Which one of the following welding processes uses non-consumable electrode? RRB JE CBT-11 31.08.2019 IInd Shift RRB JE [Exam Date: 04.01.2015 (Red Paper)] (RRB Mumbai C&G JE 25.10.2009) RRB Kolkata Apprentice Engg.-14.10.2001

  • Gas metal arc welding
  • Submerged arc welding
  • Gas tungsten arc welding
  • Flux coated arc welding

Explanation:

  • Non-consumable electrodes (made of tungsten) are used in Gas Tungsten Arc Welding (GTAW/TIG).

In TIG arc welding the welding zone is shielded by an atmosphere of —-? (RRB JE Ahamdabad2014)

  • Helium gas
  • Argon gas
  • Either (a) or (b)
  • None of these

Explanation:

  • Both Helium and Argon are inert gases and can be used as shielding gas in TIG welding.

Which of the following welding process does not uses the consumable electrode? (RRB Banglore SSE 09.09.2012)

  • Gas metal arc welding
  • Submerged arc welding
  • Gas tungsten arc welding
  • Both gas metal arc and submerged arc welding

Explanation:

  • Gas Tungsten Arc Welding (GTAW) uses a non-consumable tungsten electrode.

Consider the following statements: MIG welding process uses: (RRB Chandigarh SSE 09.09.2012)

  • Consumable electrode
  • Non-consumable electrode
  • D.C. power supply
  • A.C. power supply

Which of the following option is correct?

  • 2 and 4 are correct
  • 2 and 3 are correct
  • 1 and 4 are correct
  • 1 and 3 are correct

Explanation:

  • MIG (Metal Inert Gas) welding uses a consumable electrode and a DC power supply.

A gases used in Inert gas welding process —-? (RRB Allahabad JE 09.09.2012)

  • Hydrogen
  • Oxygen
  • Helium or Argon
  • Krypton

Explanation:

  • Inert gas welding processes like TIG and MIG use inert gases such as Helium or Argon as shielding gas.

In MIG welding, the metal is transferred in the form of —-? (RRB JE (Shift-2), 29.8.2015)

  • Weld pool
  • A fine spray
  • Spatter
  • Molecules

Explanation:

  • In MIG welding, metal is transferred in the form of a fine spray at high current, and as molten drops at low current.

The consumable electrode is used in —-? (RRB JE [Exam Date 26.08.2015 (Shift-11)] (RRB Bhabaneshwar JE-11 19.12.2010)

  • carbon arc welding
  • Submerged arc welding
  • TIG welding
  • MIG welding

Explanation:

  • MIG (Metal Inert Gas) welding uses a consumable electrode.

Which of the following welding process is also known as metal active gas welding? (Konkan Railway SSE 2015)

  • Atomic hydrogen welding
  • Submerged arc welding
  • TIG Welding
  • MAG Welding

Explanation:

  • MAG (Metal Active Gas) welding is also known as CO2 arc welding. It uses active shielding gas like CO2.

CO2 arc welding as compared to shielded metal arc welding —-? (RRB Chandigarh SSE 25.10.2009)

  • Higher efficiency
  • Lower welding costs
  • Better economy
  • All of these

Explanation:

  • CO2 arc welding offers higher efficiency, lower welding costs, and better economy compared to SMAW.

Carbon dioxide welding is also known as —-? (RRB Gorsakpur RDSO.SSE 25.10.2009)

  • Metal Active Gas Welding
  • Metal Inert Gas Welding
  • Metal Passive Gas Welding
  • Metal Passive Arc Welding

Explanation:

  • Carbon dioxide (CO2) welding is also known as Metal Active Gas (MAG) welding.

In MAG/CO2 welding which parameter give the greatest control of weld appearance during dip transfer or short-circuiting welding? (RRB Makla SSE 25.10.2009)

  • Wire stick-out length
  • Amperage
  • Wire feed speed
  • Inductance

Explanation:

  • Inductance provides the highest degree of control when dip transfer or short circuit occurs during welding.

What is main difference between MIG and MAG welding? (RRB Mumbai C&G SSE 25.10.2009)

  • Both are arc welding
  • Both used consumable electrode
  • One used argon and other used CO2 shielding gas
  • Both are semi-automatic process

Explanation:

  • MIG uses inert gas (Argon/Helium) as shielding, while MAG uses active gas (CO2).

The arc in atomic hydrogen welding takes place between the —-? (RRB Patna JE 25.10.2009)

  • parent metals
  • consumable tungsten electrode and workpiece
  • non-consumable tungsten electrode and workpiece
  • two tungsten electrodes

Explanation:

  • Atomic hydrogen welding uses an arc between two non-consumable tungsten electrodes, while hydrogen gas provides the shield.

Which of the following is an example of fusion welding? (RRB Bhopal TM SSE 25.10.2009)

  • Atomic hydrogen welding
  • Flash welding
  • Seam welding
  • Spot welding

Explanation:

  • Atomic hydrogen welding is a fusion welding process where heat is generated by an arc between two tungsten electrodes.

In atomic hydrogen welding, the electrode is made of —-? (RRB Bangalore SSE 09.09.2012)

  • carbon
  • graphite
  • tungsten
  • mild steel

Explanation:

  • In atomic hydrogen welding, the electrodes are made of tungsten.

In atomic hydrogen welding hydrogen work as —-? (RRB Corakhpur Design SSE 09.09.2012)

  • Fuel gas
  • Shielding gas
  • (a) and (b)
  • None of these

Explanation:

  • In atomic hydrogen welding, hydrogen acts as both fuel gas and shielding gas.

Atomic hydrogen welding is —-? (RRB Allahabad JE 09.09.2012)

  • Rapid welding process
  • Slow welding process
  • Moderate welding process
  • None of these

Explanation:

  • Atomic hydrogen welding is a very fast welding process with least distortion defects. It is used for welding very thin sheets or small diameter wires.

Which of the following is the function of hose pipes in the gas welding process? RRB JE Stage 2 (22.04.2025 9:00 AM-11:00 AM)

  • Mixes oxygen and acetylene in the correct proportion
  • Removes the oxide film and maintains a clean surface
  • Protects the eyes from harmful heat and ultraviolet rays
  • Supplies the gases from the pressure regulators

Explanation:

  • Hose pipes in gas welding supply oxygen and fuel gas from the pressure regulators to the welding torch.

In which type of welding flame is oxygen proportion more compared to acetylene proportion? RRB JE Stage 2 (22.04.2025 9:00 AM-11:00 AM)

  • Neutral welding flame
  • Oxidizing welding flame
  • Reducing welding flame
  • Carburizing welding flame

Explanation:

  • Oxidizing flame has more oxygen compared to acetylene. It produces a roaring sound and is useful for welding brass and brazing ferrous metals.

In carburising welding flame, there is a supply of in the combustible mixture. RRB JE Stage 2 (22.04.2025 2:30-4:30 PM)

  • acetylene and oxygen in equal proportion
  • more acetylene proportion and limited oxygen proportion
  • only oxygen
  • limited acetylene proportion and more oxygen proportion

Explanation:

  • Carburising flame has excess fuel gas (C2H2 > O2). It is used for welding medium carbon steel, nickel, etc.

In the welding technique, the welding rod is applied before the welding torch in the direction of motion. RRB JE Stage 2 (22.04.2025 2:30-4:30 PM)

  • backhand
  • electric arc
  • laser
  • forehand

Explanation:

  • In forehand welding, the welding rod is applied before the welding torch in the direction of motion.

In which type of oxy-acetylene welding flames are both acetylene and oxygen in equal proportions? RRB JE Stage 2 (22.04.2025 2:30-4:30 PM)

  • Oxidizing welding flame
  • Carburizing welding flame
  • Reducing welding flame
  • Neutral welding flame

Explanation:

  • Neutral flame is achieved when acetylene and oxygen are mixed in equal proportions (1:1 ratio).

Cyaniding involves the addition of for the hardening of surface. RRB JE 29-08-2019

  • Nitrogen
  • Niobium
  • Neon
  • Nichrome

Explanation:

  • Cyaniding involves the addition of nitrogen and carbon for hardening the surface of low carbon steel at 850°C-950°C, giving surface hardness up to 0.8mm depth.

The highest temperature obtained in oxyacetylene welding is —-? RRB JE 30-08-2019

  • 4000°C
  • 3200°C
  • 5000°C
  • 6000°C

Explanation:

  • The highest temperature obtained in oxyacetylene welding is approximately 3200°C (neutral flame).

What is the chemical symbol of acetylene gas? RRB JE 31-08-2019

  • CH2
  • CH3
  • C2H2
  • C2H2

Explanation:

  • Acetylene is a hydrocarbon with the chemical formula C2H2.

The ratio of oxygen to acetylene in the neutral flame is —-? RRB JE 31-08-2019

  • 2:1
  • 1:1
  • 3:1
  • 1:3

Explanation:

  • In a neutral flame, the ratio of oxygen to acetylene is 1:1 by volume.

The oxy-acetylene gas used in gas welding produces a flame temperature of —-? DMRC JE 17.04.2018 12:15-2:30 PM

  • 3200 degree C
  • 2400 degree C
  • 1800 degree C
  • 2100 degree C

Explanation:

  • Neutral flame temperature is around 3000°C, Oxidizing flame is 3200°C, and Carburizing flame is 2800°C.

Which flame occurs when the oxygen to acetylene ratio is 1.1 to 1? DMRC JE 17.04.2018, 4:30-6:45pm

  • Neutral flame
  • Oxidizing flame
  • Acetylene flame
  • Reducing flame

Explanation:

  • Oxygen to acetylene ratio of 1.1:1 (approximately 1:1) indicates a neutral flame, used for welding cast iron, mild steel, low carbon steel, and aluminium.

The oxy-acetylene gas used in gas welding produces a flame temperature of —-? DMRC JE 17.04.2018 12:15-2:30 PM

  • 3200°C
  • 2400°C
  • 1800°C
  • 2100°C

Explanation:

  • Neutral flame: 3000°C, Carburizing: 2800°C, Oxidizing: 3200°C.

Oxygen to acetylene ratio in case of oxidising flame is —-? (RRB Bhopal TM SSE 25.10.2009)

  • 1:1
  • 1:1
  • 1.5:1
  • 2:1

Explanation:

  • Oxidizing flame has oxygen to acetylene ratio of 1.5:1 by volume.

Oxyacetylene reducing flame is used while carrying out the welding on —-? (RRB JE (Shift-II), 29.8.2015)

  • Mild steel
  • High carbon steel
  • Grey cast iron
  • Alloy steels

Explanation:

  • Reducing or carburizing flame is used for welding high carbon steel, alloy steels, and other non-ferrous hard materials.

The acetylene cylinder is filled with a material saturated with —-? RRB SSE [Exam Date: 16-09-2015 (Shift-III)] (RRB JE (Shift-III), 16.09.2015)

  • Calcium carbide
  • Calcium oxide
  • Acetone
  • Acetylene

Explanation:

  • Acetylene cylinders are filled with a porous mass saturated with acetone to prevent explosive decomposition.

For gas welding, the pressure desired at the welding torch for oxygen is —-? RRB JE [Exam Date: 30-08-2015 (Shift-III)]

  • 7 to 103 kN/m²
  • 70 to 280 kN/m²
  • 280 to 560 kN/m²
  • 560 to 840 kN/m²

Explanation:

  • For gas welding, oxygen pressure at the torch is 70-280 kN/m², while acetylene pressure is 7-103 kN/m².

Oxygen to acetylene ratio in case of neutral flame by weight is —-? (Konkan Railway SSE 2015)

  • 0.8:1.0
  • 3:1
  • 1.2:1
  • 2:1

Explanation:

  • For neutral flame, O2:C2H2 ratio is 1:1 by volume, but by weight it is 3:1 (since 2.5 moles of O2 weigh 3 times 1 mole of C2H2).

Generally used fuel gas in gas welding is —-? (Konkan Railway TA 2017)

  • N2
  • CO2
  • C2H2
  • He

Explanation:

  • Acetylene (C2H2) is generally used as fuel gas in gas welding, mixed with oxygen.

The ratio between Oxygen and Acetylene gases for neutral flame in gas welding is —-? RRB JE CBT-11 31.08.2019 Ind Shift (Konkan Railway STA 2017)

  • 2:1
  • 1:2
  • 1:1
  • 4:1

Explanation:

  • Neutral flame has O2:C2H2 ratio of 1:1.

The most commonly used flame in gas welding is —-? (DMRC JE 20.04.2018)

  • Neutral
  • Oxidizing
  • Carburizing
  • Only Neutral and Oxidizing

Explanation:

  • Neutral flame is most commonly used for oxy-acetylene welding of steel, cast iron, aluminium, etc.

Oxygen to acetylene ratio in case of carburizing flame is —-? (DMRC JE 2013)

  • 0.5:1
  • 0.9:1
  • 1:1
  • 1:1.2

Explanation:

  • Carburizing flame has oxygen to acetylene ratio of 0.9:1.

Carburizing flame is used to weld metals like —-? (RRB Mumbai SSE 19.12.2010)

  • steel
  • copper and brass
  • aluminium, nickel, monel etc.
  • carburised steel

Explanation:

  • Carburizing flame is used for welding high carbon steel and hard-facing non-ferrous alloys like nickel and monel.

In an oxidizing flame —-? (RRB SSE (Shift-II), 01.09.2015)

  • The proportion of oxygen and acetylene gases is same
  • The proportion of oxygen gas is greater than that of acetylene gas
  • The proportion of oxygen gas is lesser than that of the acetylene gas
  • The production of oxygen and acetylene gas is not important

Explanation:

  • In an oxidizing flame, the proportion of oxygen is greater than acetylene.

In joining brass metal by gas welding, the flame adjustment should lie such that the flame is —-? (RRB SSE (shift-II), 02.09.2015)

  • a reducing one
  • an oxidizing one
  • a neutral one
  • none; since brass can be welded only by arc welding

Explanation:

  • Oxidizing flame is useful for welding brass and for brazing of ferrous metals.

In gas welding, the following type of flame is used for welding brass, bronze and gold —-? (RRB Mumbai JE 05.10.2008)

  • neutral flame
  • reducing flame
  • oxidizing flame
  • both neutral and reducing flames

Explanation:

  • Oxidizing flame (O2:C2H2 = 1.5:1) is used for welding brass, bronze, and gold.

In forehand gas welding operation, the angle between the rod and work is kept around —-? (RRB Allahabad SSE 19.12.2010)

  • 30°
  • 45°
  • 60°
  • 75°

Explanation:

  • In forehand welding, the rod is applied before the torch at roughly a 30° angle. This technique is used for plates less than 6mm thickness.

In the following welding technique, the flame of the torch is directed against the completed weld —-? (RRB Allahabad JE 19.12.2010)

  • overhead welding
  • horizontal welding
  • forehand welding
  • backhand welding

Explanation:

  • In backhand welding, the flame is directed against the completed weld. This method is better for plates over 6mm thickness.

Which of the following is NOT a type of gas flame used in gas welding/cutting? (RRB Bhubneshwar JE-11 19.12.2010)

  • Oxidising
  • Reducing
  • Cyaniding
  • Neutral

Explanation:

  • Cyaniding is a case hardening method, not a type of gas flame. The three types of gas flames are Oxidising, Reducing, and Neutral.

Which of the following gas welding flame decarburized the steels? (BMRCL JE 24 Feb.2019)

  • Neutral flame
  • Oxydising flame
  • Carburising flame
  • None of these

Explanation:

  • Oxidising flame is used for decarburizing of steel (reducing carbon content).

Which of the following not a limitations of gas welding? (JMRC JE 10.06.2017)

  • Not required pressure during welding
  • A fusion welding
  • Cannot be used for cast iron
  • Used of flax

Explanation:

  • Gas welding can be used for cast iron. It is a fusion welding process that does not require pressure.

____ is used for mixing oxygen and acetylene in gas welding processes. RRB JE (Re-Exam) 04.06.2025

  • Goggles
  • Earth clamp
  • Welding torch
  • Spark-lighter

Explanation:

  • Welding torch (also called blowpipe) is used for mixing oxygen and acetylene in gas welding processes.

Oxygen cylinders are —-? (DMRC JE 22.09.2017)

  • cast iron cylinders
  • steel cylinders, welded structure
  • die cast
  • seamless steel cylinders

Explanation:

  • Oxygen cylinders are made of seamless steel.

Oxygen cylinders are coloured with —-? (RRB Bhubneshwar JE-11 19.12.2010)

  • Black
  • White
  • Red
  • Green

Explanation:

  • Oxygen cylinders are coloured black. Acetylene cylinders are maroon, hydrogen cylinders are red, argon cylinders are blue, and nitrogen cylinders are grey.

Acetylene cylinders are coloured with —-? (RRB Allahabad SSE 19.12.2010)

  • Black
  • White
  • Maroon
  • Green

Explanation:

  • Acetylene cylinders are coloured maroon.

Acetylene dissolved in —-? (RRB Mumbai JE 19.12.2010)

  • Acetone
  • Butane
  • Methyl acetylene propadiene
  • H2O

Explanation:

  • Acetylene is dissolved in acetone in cylinders to prevent explosive decomposition.

In high pressure welding acetylene pressure is —-? (DMRC JE 20.04.2018)

  • 25 kg/cm²
  • 15 kg/cm²
  • 20 kg/cm²
  • 35 kg/cm²

Explanation:

  • In high pressure welding, acetylene pressure is 15 kg/cm².

Melting temperature of fusible plug placed in acetylene gas cylinder is —-? (RRB Kolkata Diesel JE 25.10.2009)

  • 80°C
  • 104°C
  • 154°C
  • 184°C

Explanation:

  • Acetylene cylinders have a fusible plug which melts at about 100°C (104°C).

Single stage regulator mostly used in —-? (RRB Mumbai C&G JE 25.10.2009)

  • Gas welding
  • Gas cutting
  • Gas purifier
  • None of these

Explanation:

  • Single stage regulators are mostly used in gas cutting applications.

Difference between oxygen and acetylene regulators —-? (RRB Jammu JE 25.10.2009)

  • Both have right hand threads
  • Both used for high pressure
  • Both coloured by black paint
  • None of these

Explanation:

  • Oxygen regulator has right-hand thread, is painted black, and is heavier. Acetylene regulator has left-hand thread, is painted maroon, and is lighter.

Purpose of hose pipe used in gas welding deliver —-? (RRB Allahabad JE 25.10.2009)

  • Oxygen gas
  • Acetylene gas
  • Both (a) and (b)
  • None of these

Explanation:

  • Hose pipes in gas welding deliver both oxygen and acetylene gas.

Gas welding torch also known as —-? (RRB Patna JE 25.10.2009)

  • Hose pipe
  • Blowpipe
  • Torch lighter
  • Injector

Explanation:

  • Gas welding torch is also known as blowpipe.

Which blow pipe will be used when oxygen and acetylene gas pressure are equal? (RRB Allahabad SSE 09.09.2012)

  • High pressure blow pipe
  • Low pressure blow pipe
  • Automatic blow pipe
  • Semi-automatic blow pipe

Explanation:

  • When oxygen and acetylene gas pressures are equal, a high pressure blow pipe is used.

Which of the following gas welding equipments used when large amount of acetylene consumption? (RRB Kolkata SSE 09.09.2012)

  • Acetylene generator
  • Cylinder manifold
  • Pressure regulator
  • Blow pipe

Explanation:

  • When large amounts of acetylene are consumed, it is cheaper to generate it on-site using an acetylene generator.

To provide maximum amount of gas, series connection of many gas cylinder for large gas welding job, is called —-? (RRB Chandigarh SSE 09.09.2012)

  • Gas tank
  • Cylinder generator
  • Hose
  • Cylinder manifold

Explanation:

  • A cylinder manifold interconnects multiple cylinders to a common gas supply line when consumption is high.

Which of the following gas impurities removed by gas purifier? (RRB Allahabad JE 09.09.2012)

  • NH3
  • H2S
  • CO2
  • All of these

Explanation:

  • A gas purifier removes impurities like Hydrogen Sulfide (H2S), Carbon Dioxide (CO2), and Ammonia (NH3) from acetylene gas.

Hydraulic back pressure valve also known as —-? (RRB Bhubneshwar JE 17 29.11.2008)

  • Water seal
  • Outlet cock
  • Maintaining cock
  • Gas inlet

Explanation:

  • Hydraulic back pressure valve is also known as a water seal. It is a safety device that protects the generator from backfire.

Back gas welding nozzle back fire prevented by —-? (DMRC JE 22.09.2017)

  • Lock pin
  • Safety pin
  • Tip pin
  • None of these

Explanation:

  • Backfire in the nozzle is prevented by a safety pin.
RRB JE Mechanical- Welding Questionbank 2