question_answer

Which of the following pattern-materials are used in Precision Casting?

1. Plaster of Paris

2. Plastics

3. Anodized aluminium alloy

4. Frozen mercury

Select the correct answer using the codes given below:

Codes:

A) 1 and 2            

B) 2 and 4

C) 3 and 4            

D) 1 and 3