1. Steel containing upto 0.15% carbon, is known as ?

mild steel

dead mild steel

medium carbon steel

high carbon steel

Answer: dead mild steel

Explanation:


2. Which of the following impurity in cast iron makes it hard and brittle ?

Silicon

Sulphur

Manganese

Phosphorus

Answer: Sulphur

Explanation:


3. Specify the sequence correctly ?

Grain growth, recrystallisation, stress relief

Stress relief, grain growth, recrystallisation

Stress relief, recrystallisation, grain growth

Grain growth, stress relief, recrystallisation

Answer: Stress relief, recrystallisation, grain growth

Explanation:


4. In a unit cell of a body centred cubic space lattice, there are .................. atoms ?

six

nine

fourteen

seventeen

Answer: nine

Explanation:


5. For a steel containing 0.8% carbon ?

there is no critical point

there is only one critical point

there are two critical points

there can be any number of critical points

Answer: there is only one critical point

Explanation:


6. An alloy steel which is work hardenable and which is used to make the blades of bulldozers, bucket wheel excavators and other carth moving equipment contain iron, carbon and ?

chromium

silicon

manganese

magnesium

Answer: manganese

Explanation:


7. In the austempering process of heat treatment, austenite changes into ?

martensite

troostite

sorbite

bainite

Answer: bainite

Explanation:


8. A steel alloy containing 36% nickel is called ?

stainless steel

high speed steel

invar

heat resisting steel

Answer: invar

Explanation:


9. The coordination number of a face centred cubic space lattice is ?

six

twelve

eighteen

twenty

Answer: twelve

Explanation:


10. The steel widely used for motor car crankshafts is ?

nickel steel

chrome steel

nickel-chrome steel

silicon steel

Answer: chrome steel

Explanation: