40) Failure of a material below yield point stress due to repeated stresses is called

Answer is:

Fatigue

Material science MCQ with Answers

41) The bed of a lathe is made out of

Answer is:

Cast iron

Explanation:

Cast iron is commonly used for machinery housings or base due to its damping characteristics. It is also known for holding its shape when it is subjected to contraction and expansion due to temperature fluctuations. Hence lathe bed is usually made up of cast iron.