Consider the following statements.
1. Blowholes in the castings are caused due to excess moisture.
2.Hot tears are caused due to to high pouring temperature.
3.Swells are caused due to low temperature of molten metal.
4.Warapage are caused due to faulty metal composition.
Which of the following statements are correct?
1
1 only
2
2 and 3
3
3 and 4
4
1 and 2