Engineering Questions with Answers - Multiple Choice Questions
Mechanical Operations MCQ’s – Crushing Efficiency
1 - Question
Which of the following works on principle of compression and impact?
a) Jaw crusher
b) Gyratory crusher
c) Fine crusher
d) Tramp crusher
View Answer
Answer: b
Explanation: The gyratory crusher involves the operation of both compression and impact at the same time, while jaw crusher only applies compression.
2 - Question
The feed size of gyratory crusher varies from ____
a) 150-190 mm
b) 200-800 mm
c) 500-600 mm
d) 100-150 mm
View Answer
Answer: a
Explanation: The minimum acceptable feed in a gyratory crusher ranges from 150 to 900 mm and product ranges from 1 to 10 inches.
3 - Question
The capacity of a gyratory crusher is ____
a) 3000 T/hr
b) 4000 T/hr
c) 500 T/hr
d) 100 T/hr
View Answer
Answer: a
Explanation: The gyratory crusher operates at a capacity of 3000 tons/hour and during this duration the crushing head speed is 125 to 425 gyrations per minute.
4 - Question
Which of the following involves impact and attrition operations?
a) Rod mill
b) Jaw crusher
c) Hammer mill
d) Timber
View Answer
Answer: c
Explanation: The hammer mill uses the principle of impact and attrition operations for size reduction, while jaw and rod mill are based on the compression techniques.
5 - Question
Hammer mill has usually has ____ hammers pinned.
a) 4, 6 or 8
b) Only 4
c) Only 6
d) Only 8
View Answer
Answer: a
Explanation: Hammer mill usually consist of 4, 6 or 8 sets of hammers pinned, it also consists of the screen at the discharge opening.
6 - Question
Which of the following is feed size for a hammer mill?
a) 50 inches
b) 10 inches
c) 60 inches
d) 70 inches
View Answer
Answer: b
Explanation: The feed size for a hammer mill is 10 inches, while the product size ranges from 1 inch to 20 mesh or 200 mesh
7 - Question
Which of the following is the capacity of the hammer mill?
a) 0.2 to 2 T/hr
b) 6 to 8 T/hr
c) 5 to 10 T/hr
d) 0.1 to 15 T/hr
View Answer
Answer: d
Explanation: The capacity of the hammer mill is 0.1 to 15 T/hr, while during this duration peripheral speed of the hammer is 112 m/s.
8 - Question
Which of following is used for fine crushing?
a) Stump battery
b) Jaw crusher
c) Dodge crusher
d) Camp crusher
View Answer
Answer: a
Explanation: The stamp battery is used extensively used for fine crushing, stamp battery consists of several stamps weighing 500-1000 kg in weight.
9 - Question
The roll crushers’ diameters are of ____
a) 10 inches
b) 12 inches
c) 24 inches
d) 20 inches
View Answer
Answer: c
Explanation: They are 24 inches in diameter with 12 inch face and 78 inches in diameter with 36 inch face.
10 - Question
Which of the following is the capacity of a roll crusher?
a) 1 to 50 T/hr
b) 3 to 120 T/hr
c) 4 to 120 T/hr
d) 5 to 100 T/hr
View Answer
Answer: b
Explanation: The capacity of a roll crusher is 3 to 300 T/hr and the roll speed ranges from 50 to 300 revolution per minute.