2. Half the angle of nip, (?), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively).
4. Pick out the wrong statement pertaining to the turbine agitator.
Options
A. Recommended peripheral speed for the turbine agitator is 200-250 metres/minute.
B. Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow.
C. Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with central disc, it is l/8th of the agitator diameter).
D. Turbine agitator should be located at a height not less than one agitator diameter length from the bottom. If the depth of liquid in the tank is more than twice the agitator diameter, two agitators should be used.