1. In magnesium alloys, the water content in percentage is 10%.
a) True
b) False
Explanation: In magnesium alloys, the water content in terms of percentage is not 10%. The amount of water in terms of percentage composition is much lower than that. The composition of water around 2%
2. How much time does a centrifugal muller take to mix the core ingredients?
a) 20 – 50 seconds
b) 10 – 40 seconds
c) 50 – 80 seconds
d) 60 – 90 seconds
Explanation: A centrifugal muller takes around 60 seconds to 90 seconds to get the core ingredients mixed properly, whereas a normal muller takes about 4 minutes for mixing the ingredients.
3. How much time does a normal muller take to mix the core ingredients?
a) 2 – 5 minutes
b) 3 – 6 minutes
c) 4 – 7 minutes
d) 5 – 9 minutes
Explanation: A normal muller takes around 3 minutes to 6 minutes to get the core ingredients mixed properly, whereas a centrifugal muller takes around 30 seconds to one minute to mix the core ingredients.
4. What is the baked tensile strength of light to medium size malleable iron castings?
a) 4.5 kg/cm2
b) 5.5 kg/cm2
c) 6.5 kg/cm2
d) 7.5 kg/cm2
Explanation: There are many types of cast irons which have differing properties, according to the type of manufacture and the quantity of ingredients used. The baked tensile strength of light to medium size malleable iron casts is 5.5 kg/cm2.
5. What is the dry tensile strength of core sand mixture for general purpose?
a) 15 kg/cm2
b) 16 kg/cm2
c) 17 kg/cm2
d) 18 kg/cm2
Explanation: There are various properties of core sand mixture which widely depend on many factors. The dry tensile strength of core sand mixture for general purpose is 17 kg/cm2.
6. What is the dry compression strength of core sand mixture for general purpose?
a) 50 kg/cm2
b) 60 kg/cm2
c) 70 kg/cm2
d) 80 kg/cm2
Explanation: The dry compression strength of core sand mixture for general purpose is 70 kg/cm2, and the dry tensile strength of the of a core sand mixture is calculated to be 17 kg/cm2.
7. What is the green compression strength of core sand mixture for general purpose?
a) 1/5 kg/cm2
b) 1/6 kg/cm2
c) 1/7 kg/cm2
d) 1/8 kg/cm2
Explanation: The green compression strength of core sand mixture for general purpose is 1/7 kg/cm2, whereas the dry compression strength of a core sand mixture is found to be 70 kg/cm2.
8. What is the green compression strength of light to medium size malleable iron castings?
a) 0.05 kg/cm2
b) 0.06 kg/cm2
c) 0.07 kg/cm2
d) 0.08 kg/cm2
Explanation: The green compression strength of light to medium size malleable iron casts is 0.08 kg/cm2, whereas the dry compression strength of a core sand mixture is found to be 70 kg/cm2.
9. What is the water content in light to medium size malleable iron castings?
a) 3.2%
b) 4.2%
c) 5.2%
d) 6.2%
Explanation: The water content in terms of percentage composition in light to medium size malleable iron castings is calculated to be not much in it. The amount of water content found in the casting is about 4.2%
10. What is the amount of green permeability in light to medium size malleable iron castings?
a) 34 cc/min
b) 44 cc/min
c) 54 cc/min
d) 64 cc/min
Explanation: The rate of green permeability is quite a decent one. The amount of green permeability in light to medium size malleable iron castings is 44 cc/min.