A. μ > tan α
B. μ ≥ tan α
C. μ > tan 2α
D. μ ≤ tan α
Related Mcqs:
- 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) - 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° - Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity ?
A. Sphere
B. Cube
C. Cylinder (L/D = 1)
D. Raschig rings - Sphericity for a non-spherical particle is given by (where, V and S are volume and surface area respectively of one particle. and, D = equivalent diameter of particle)?
A. 6.V/D.S
B. V/6D.S
C. D.S/V
D. V/D.S - 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 - The term ‘angle of nip’ is concerned with the operation of the ____________ crushers?
A. Jaw
B. Roll
C. Gyratory
D. None of these - The value of ‘angle of nip’ is generally about__________________?
A. 16°
B. 32°
C. 52°
D. 64° - Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) ?
A. m/ρ . Vp
B. m . ρ/Vp
C. m . Vp/ρ
D. Vp/m . ρ - In a grinding operation, the limiting particle size is the size of the _______________ particle in the sample?
A. Smallest
B. Largest
C. Either A. or B.
D. Neither A. nor B. - 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
