Practice Pakistan's most useful MCQs for competitive exams

Refractory bricks are usually dried in a ________________ dryer?

• (A)  Tray
• (B)  Tunnel
• (C)  Conveyor
• (D)  Festoon

Answer

Submitted By :Ali Uppal

The most common packing used in industrial operations is _______________ rings?

• (A)  Raschig
• (B)  Lessing
• (C)  Cross-partition
• (D)  Single spiral

Answer

Submitted By :Ali Uppal

Sphericity of raschig ring (whose length and diameter are equal) is___________________?

• (A)  > 1
• (B)  < 1
• (C)  1
• (D)  2

Answer

Submitted By :Ali Uppal

Energy consumed for crushing one ton of material ranges from ______________ kWh?

• (A)  0.01 to 0.1
• (B)  0.5 to 1.5
• (C)  2 to 3.5
• (D)  4 to 5

Answer

Submitted By :Ali Uppal

Dust collection efficiency of electrostatic precipitator can be as high as 99.9%. Maximum temperature and pressure of dust laden gas that can be cleaned in an electrostatic precipitator is respectively ?

• (A)  200°C and 5 atm
• (B)  1000°C and 10 atm
• (C)  500°C and 50 atm
• (D)  1000°C and 500 atm

Answer

Submitted By :Ali Uppal

Separation of materials of the same density based on their sizes by using then-different rates of flow is called__________________?

• (A)  Sorting
• (B)  Sizing
• (C)  Flocculation
• (D)  Elutriation

Answer

Submitted By :Ali Uppal

The specific surface of spherical particles is proportional to (where, Dp = diameter of particle)?

• (A)  D2
• (B)  Dp
• (C)  1/Dp
• (D)  1/D2p

Answer

Submitted By :Ali Uppal

Which of the following agitators having a large blade area, rotating at slow speed is used for mixing high viscosity liquids (> 50000 centipoise) ?

• (A)  Propeller
• (B)  Helical screw
• (C)  Flat blade turbine
• (D)  Curved blade turbine

Answer

Submitted By :Ali Uppal

Filtrate flow rate in case of a rotary drum vacuum filter (in which Rm < < Rc) is proportional to ____________ and the cycle time (where, μ = filtrate viscosity Rm = filter medium resistance Rc = cake resistance)?

• (A)  √μ
• (B)  1/√μ
• (C)  1/μ
• (D)  1/μ2

Answer

Submitted By :Ali Uppal

Flow of filtrate through the cake in a plate and frame filter press is best described by the ______________ equation?

• (A)  Kozeny-Carman
• (B)  Hagen-Poiseuille’s
• (C)  Fanning’s
• (D)  Kremser

Answer

Submitted By :Ali Uppal