The value of ‘angle of nip’ is generally about__________________?

Related Mcqs:

1. What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls?

   A. 16°
   B. 32°
   C. 40°
   D. 46°

2. Angle of nip of the crushing rolls does not depend upon the_______________?

   A. Diameter of the rolls
   B. Speed of the rolls
   C. Product size
   D. Feed size

3. Which of the following relationships between co-efficient of friction (μ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct ?

   A. μ > tan α
   B. μ ≥ tan α
   C. μ > tan 2α
   D. μ ≤ tan α

4. Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively) ?

   A. cos α = (dr + dp)/(dr + df)
   B. cos α = (dr + df)/(dr + dp)
   C. tan α = (dr + dp)/(dr + df)
   D. sin α = (dr + dp)/(dr + df)

5. The term ‘angle of nip’ is concerned with the operation of the ____________ crushers?

   A. Jaw
   B. Roll
   C. Gyratory
   D. None of these

6. Reciprocating screens are normally inclined at an angle of 5° with the horizontal and employ gyratory motion at feed end & reciprocating motion at the discharge end. They are not suitable for the screening of the ___________________?

   A. Light metal powder down upto 4 mesh size
   B. Dry chemicals
   C. Heavy tonnages of rocks or gravel
   D. Powdered food & granular materials

7. Tabling process used for separating two materials of different densities by passing the dilute pulp over a table/deck, which is inclined from the horizontal surface at an angle of about________________?

   A. 1 to 2°
   B. 2 to 5°
   C. 5 to 10°
   D. 10 to 15°

8. The value of work index does not change materially from one equipment to another. If the value of work index determined for close circuit grinding is Wi, then the same for open circuit grinding will be_________________?

   A. 0.5 Wi
   B. Wi
   C. 1.34 Wi
   D. 3.34 Wi

9. Mixing of plastic solids is generally facilitated by___________________?

   A. Dispersion
   B. Mastication
   C. Kneading
   D. None of these

10. Stamp mills are generally used for crushing__________________?

    A. Iron ores
    B. Gold ores
    C. Talc
    D. Diamond