Materials and Construction

341. Sulphur melting pit in the sulphuric acid plant is made of

1. Lead lined stainless steel
2. Cast iron
3. Steel or cement-brick lined
4. Hard wood

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342. Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with

1. Acidic refractory
2. Rubber
3. Karbate
4. Lead or acid-proof bricks

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343. Sulphuric acid pickling tanks are lined with

1. Nickel
2. Rubber
3. Aluminium
4. Glass

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344. Tank furnace used for melting of glass is made of

1. Mild steel
2. Cast iron
3. Refractory blocks
4. Stainless steel

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345. Teflon (PTFE) is corroded by

1. Hydrochloric acid (10%)
2. Hydrochloric acid (95%)
3. Sulphuric acid
4. None of these

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346. Tempering of steel is done to make it

1. Brittle
2. Hard
3. Rollable
4. Soft

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347. The 'bomb' in the bomb calorimeter is made of

1. Molybdenum stainless steel
2. Mild steel
3. High silicon iron (14% Si)
4. Copper

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348. The ability of a material to absorb energy in the elastic range is a measure of its

1. Toughness
2. Resilience
3. Malleability
4. Brittleness

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349. The ability of a material to offer resistance to scratching or indentation is a measure of its

1. Brittleness
2. Toughness
3. Hardness
4. Resilience

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350. The addition of antimony in tin-based alloys improves its

1. Rupture strength and hot hardness
2. Impact strength and bonding strength
3. Deformation resistance
4. Wear resistance

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