Question

Consider the following statements:
Statement-I: In TIG welding, electrode consumption contributes to metal deposition
Statement-II: MIG welding is preferred for automation due to continuous wire feeding
Statement-III: MMAW electrodes require controlled storage conditions

• A. Statement-I and Statement-II are true
• B. Statement-II and Statement-III are true
• C. Statement-I and Statement-III are true
• D. Statement-I, Statement-II and Statement-III are true

Hint:

TIG uses non-consumable electrode, MIG uses continuous consumable wire, and MMAW electrodes must be kept dry to avoid hydrogen defects.

Answer 1

The Correct Option is B

Concept: Welding processes are broadly classified based on:
• type of electrode (consumable or non-consumable)
• shielding mechanism
• mode of metal deposition
• suitability for automation Each welding process behaves differently in terms of electrode consumption and process control.

Step 1: Analyze Statement-I (TIG welding). TIG welding (Tungsten Inert Gas welding) uses a non-consumable tungsten electrode. The electrode:
• does NOT melt to contribute filler metal
• only produces arc for heating
• filler rod is separately added if required Thus, metal deposition does NOT come from electrode consumption. \[ \text{Statement-I is FALSE} \]

Step 2: Analyze Statement-II (MIG welding). MIG welding (Metal Inert Gas welding) uses a:
• consumable wire electrode
• continuous wire feeding mechanism This continuous feed system ensures:
• high deposition rate
• ease of automation
• uniform weld quality Therefore, MIG welding is widely used in robotic and automated systems. \[ \text{Statement-II is TRUE} \]

Step 3: Analyze Statement-III (MMAW electrodes). MMAW (Manual Metal Arc Welding) uses coated electrodes that:
• absorb moisture from atmosphere
• lead to hydrogen-induced cracking if not controlled
• require dry storage conditions (oven storage) Hence, controlled storage is essential. \[ \text{Statement-III is TRUE} \]

Step 4: Final evaluation. \[ \text{Statement-I = False, Statement-II = True, Statement-III = True} \] Thus correct option is: \[ \boxed{\text{(B) Statement-II and Statement-III are true}} \]