Riser Design MCQs : Here you will find MCQ Questions related to "Riser Design" in Casting, Forming & Welding. These Riser Design MCQ Questions Will help you to improve your Casting, Forming & Welding knowledge and will prepare you for various Examinations like Competitive Exams, Placements, Interviews and other Entrance Exmaniations.
Question 1
How can we eliminate the shrinkage cavity?
A. By increasing riser height
B. By reducing riser height
C. Reducing the number of risers
D. By using an open riser
View Answer
Ans : A
Explanation: If riser height is reduced, the pipe will extend to cast cavity. Similarly, if less no of the riser is used it will not satisfy feeding distance. Open riser alone can’t help in reduction of the cavity. But by increasing length of the riser, the pipe can be controlled in riser itself eliminating shrinkage cavity in casting.
Question 2
Which of the following can be used for increasing feeding distance?
A. Uniform temperature gradient
B. Negative temperature gradient towards the riser
C. No temperature gradient
D. Positive temperature gradient towards the riser
View Answer
Ans : D
Explanation: If the temperature gradient is not there, the metal will not solidify. Same will happen in case of the uniform temperature gradient. In case of the negative thermal gradient, the metal will first solidify near riser which results in unsound casting. Hence positive thermal gradient is required so that metal will solidify near walls first hence feeding distance will be increased.
Question 3
How can we enhance the feeding distance during casting?
A. Reducing molten metal temperature
B. Increase fluidity
C. By using low thermal conductivity mold
D. Using sand mold
View Answer
Ans : B
Explanation: Feeding distance reduces by reducing molten metal temperature and using a low thermal conductive mold. For sand casting, feeding distance will be low because heat extracted by sand is very less compared to metals. By increasing fluidity, metal can flow over a long distance which results in higher feeding distance.
Question 4
How can we calculate the solidification time?
A. Shrinkage volume consideration method
B. Modulus method
C. Novel research method
D. Chvorinovs rule
View Answer
Ans : D
Explanation: Shrinkage volume consideration method, Modulus method, and Novel research method are used for riser design. For calculation of solidification time, Chvorinov’s Rule is used. The Same rule can be modified for riser design called as Caine’s method.
Question 5
If feeding distance is more, the number of risers required will be more.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : B
Explanation: Feeding distance is more implies molten metal can flow for a longer distance. This will result in very few mushy zones in the casting. Hence, if the mushy zone is less, the number of risers required will also be less.
Question 6
Which of the following materials can have the negative volumetric shrinkage of the casting?
A. Aluminium
B. Steel
C. Zinc
D. Grey Cast Iron
View Answer
Ans : D
Explanation: Different materials have different volumetric shrinkage, in which grey cast iron is the material which sometimes may have a negative shrinkage. This mainly occurs because of high carbon and silicon contents in the grey cast iron, which results in occurring of graphitization which increases the volume.
Question 7
The cooling characteristics of casting can be represented by the_____
A. volume to surface area ratio
B. product of volume and surface area
C. surface area to volume ratio
D. surface area to perimeter ratio
View Answer
Ans : C
Explanation: Solidification is basically occurred by losing heat from the surfaces and the amount of the heat is given by the volume of the casting, and the cooling characteristics of casting are given by the surface area to volume ratio. Riser is also similar to the casting in its solidification nature; hence the riser characteristics can also be given by the ratio of its surface area to volume.
Question 8
There is no requirement of any risers for the casting of grey cast iron.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : A
Explanation: In grey cast iron, while solidification the process of graphitization occurs, this increases the volume of the casting and counteracts the metal shrinkage, so risers can be eliminated for the casting of grey cast iron. But for some metals like aluminium and steel, the volumetric contraction is very high, so elaborate risering is required.
Question 9
Which of the following factors is used to define the casting type in riser design?
A. Plating factor
B. Ranginess factor
C. Caine factor
D. Pseudo factor
View Answer
Ans : B
Explanation: For the chunky type castings like a cube, the volume component can be neglected, but for the rangy castings, like as plate-like casting, the influence of the volume part becomes increasingly significant. So, it is very useful to have a parameter called ranginess factor (R), to define the casting type.
Question 10
In casting system, the riser is located at the lightest section to avoid any disturbance.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : B
Explanation: In the casting system, the risers should be located at the heaviest sections to achieve a better casting with fewer defects, and because the heavier sections, themselves act as feeders for the thin sections. And variations in volume of riser must be done if the size of casting sections also varies.