Practice Pakistan's most useful MCQs for competitive exams

Handling of ashes and similar materials can be done best by a ______________ conveyor?

• (A)  Flight
• (B)  Drag or slat
• (C)  Belt
• (D)  Ribbon

Answer

Submitted By :Ali Uppal

Size reduction mechanism used in Jaw crushers is__________________?

• (A)  Attrition
• (B)  Compression
• (C)  Cutting
• (D)  Impact

Answer

Submitted By :Ali Uppal

Wet sieving is employed, when the product contains ________________ materials?

• (A)  Abrasive
• (B)  Large quantity of very fine
• (C)  Coarse
• (D)  Non-sticky

Answer

Submitted By :Ali Uppal

According to Taggart’s rule for selecting between a gyratory crusher and a jaw crusher; the later should be used, if the hourly tonnage to be crushed divided by the square of the gape expressed in cm is less than_______________?

• (A)  0.00184
• (B)  0.0184
• (C)  0.184
• (D)  1.84

Answer

Submitted By :Ali Uppal

What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls ?

• (A)  0.5
• (B)  1.0
• (C)  2.76
• (D)  0.66

Answer

Submitted By :Ali Uppal

The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond’s law) of the energy to grind the particles from a very large size to 50 μm is________________?

• (A)  6.35 kWh/ton
• (B)  9.0 kWh/ton
• (C)  18 kWh/ton
• (D)  25.4 kWh/ton

Answer

Submitted By :Ali Uppal

_______________ mill is not used for grinding wheat into flour and for milling of cereals & other ?

• (A)  Buhrstone
• (B)  Roller
• (C)  Attrition
• (D)  Pebble

Answer

Submitted By :Ali Uppal

Jigging is a technique by which different particles can be____________________?

• (A)  Separated by particle size
• (B)  Separated by particle density
• (C)  Separated by particle shape
• (D)  Mixed

Answer

Submitted By :Ali Uppal

For the preliminary breaking of hard rock, we use a____________________?

• (A)  Gyratory crusher
• (B)  Ball mill
• (C)  Tube mill
• (D)  Squirrel-cage disintegrator

Answer

Submitted By :Ali Uppal

For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a__________________?

• (A)  Buhrstone mill
• (B)  Ball mill
• (C)  Crushing rolls
• (D)  Hammer mill

Answer

Submitted By :Ali Uppal