Pick out the wrong statement.

• Gape is the greatest distance between the crushing surfaces or the jaws.
• The angle of nip (2α) is the angle between roll faces at the level where they will j ust take hold of a particle and draw it in the crushing zone.
• Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing.
• Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product.