1.What is the relation between Kb and Wi?
a) Kb = Wi
b) Kb = √DWi
c) KbWi = √D
d) Kb/Wi = √D
Answer: b [Reason:] The relation between Kb and Wi can be mathematically defined as Kb = √DWi, where D is the diameter size of the particle.
2.What is the value of x, if Kb = x*Wi?
Answer: a [Reason:] As Kb= √(100*10-3 Wi ) = 0.3162*Wi, hence the value of x is 0.3162.
3. Which of the following is a type of coarse crusher?
a) Rod mill
b) Stamp battery
c) Jaw crusher
Answer: c [Reason:] The jaw crusher is one of the major type of the coarse crushing equipment, while stamp and rod mill are of the fine crushers category.
4. Which of the following works principle of compression?
a) Knife cutter
b) Blake jaw crusher
c) Gyratory Crusher
d) Rod mill
Answer: b [Reason:] The jaw crusher works on the principle of the compression, it consists of a pair of jaw between which the feed is crushed.
5. The stationary and moveable jaw in a jaw crusher are called as ____
a) Cramp and Anvil
b) Moving and Stay
c) Anvil and Swinging
d) Trace and Find
Answer: c [Reason:] In a jaw crusher, the pair of jaw is available where one of the jaw is fixed, called anvil and the other jaw is called as the swinging jaw.
6. The maximum feed size for jaw crusher is ____
a) 6 feet in diameter
b) 10 feet in diameter
c) 20 feet in diameter
d) 5 feet in diameter
Answer: a [Reason:] The maximum feed size for jaw crusher is 6 feet in diameter and the product size thus obtained is either ¼ or 10 inches of diameter.
7. The capacity of a jaw crusher is ____
a) 10 to 20 tons/hour
b) 50 to 60 tons/hour
c) 100 to 500 tons/hour
d) 9 to 900 tons/hour
Answer: d [Reason:] The capacity of a jaw crusher is 9 to 900 tons/hour, during this time the jaw open and closes 250 to 400 times per minutes.
8. In a dodge crusher, the moveable jaw is fixed at _____
Answer: a [Reason:] A dodge crusher also consist of two jaws, which are moveable and are fixed at the bottom of the crusher body.
9. Which of the following shows the tendency to choke?
a) Jaw crusher
b) Dodge Crusher
c) Rod mill
d) Gyratory crusher
Answer: b [Reason:] The dodge crusher is the most prone to the tendency of choking and thus is less widely used due to the same reason.
10. Calculate D. If Kb = 105.6 and Wi = 5?
Answer: a [Reason:] As Kb = √DWi , then Kb/Wi = √D , 105.6/5 = √21.12 = 449.44 mm.