Question: Pick out the wrong statement ?

• 1. Plate efficiency increases with increase in superficial vapour velocity till entrainment limit
• 2. Increase in depth of the liquid about the slots increases the plate efficiency, particularly if the liquid depth is < 1"
• 3. Too small a plate spacing can cause a low efficiency, if the vapour velocity is greater than the allowable value
• 4. None of these

Question: Pick out the wrong statement?

• 1. In practical operation, distillation towers having diameter 3-6 metres equipped with bubble cap (round) size of 15 cms are used
• 2. Height of packing in a packed tower is about 3 times the column diameter for raschig rings and about 5 to 10 times the column diameter for saddle packing
• 3. In a sieve tray, the minimum hole diameter is equal to the tray thickness
• 4. In a stainless steel sieve tray, the minimum hole diameter is equal to 10 times the plate thickness

Question: ______________ bricks should not be used in oxidising atmosphere?

• 1. Tar dolomite
• 2. Carbon
• 3. Silica
• 4. Fireclay

Question: Magnesite bricks have poor resistance to attack by _____________ slag?

• 1. Lime
• 2. Basic
• 3. Acid
• 4. None of these

Question: Which is not a natural insulating material ?

• 1. Diatomaceous earth/kieselgur
• 2. Asbestos
• 3. Vermiculite
• 4. None of these

Question: Which of the following is not a high alumina refractory material ?

• 1. Kyanite
• 2. Sillimanite
• 3. Diaspore
• 4. Periclase

Question: ___________________ is the measure of the strength of refractory under the combined effect of temperature & load ?

• 1. Porosity
• 2. RUL
• 3. Specific gravity
• 4. Thermal conductivity

Question: Which one contains minimum percentage of SiO2 ?

• 1. Firebrick
• 2. Sillimanite
• 3. Semi-silica
• 4. Aluminous firebrick

Question: Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as _____________ percent?

• 1. 55
• 2. 70
• 3. 80
• 4. 90

Question: Mullite is chemically represented by_________________?

• 1. Al2O3. 2SiO2
• 2. 3Al2O3. 2SiO2
• 3. Al2O3. SiO2
• 4. 2Al2O3. 3SiO2