A. Suppresses the decomposition of Fe3C
B. Increases the formation of graphite
C. Increases the contraction of the metal
D. Reduces its fluidity
Related Mcqs:
- Straight silicon steel (containing Si from 0.5 to 5%) because of their low hysteresis loss and high magnetic permeability are used for electrical appliances. Which of the following electrical appliances made of silicon steel contains maximum percentage of silicon (about 4%) ?
A. Armature of small motors/generators
B. Generators and small motors
C. Induction motors
D. High frequency transformers - Containers made of high silicon cast iron (14% Si) are not suitable for the storage of ____________________?
A. Acetic acid
B. Benzoic & boric acids
C. Phosphoric acid (95%) & sulphuric acid (95%)
D. Hydrochloric acid (concentrated) - Presence of high phosphorous in cast iron increases its____________________?
A. Fluidity
B. Melting point
C. Shrinkage
D. Tensile strength - Silicon percentage in acid resistant cast iron is about________________?
A. 4
B. 8
C. 14
D. 20 - Presence of silicon in steel_____________________?
A. Is in the form of free Si
B. Indicates that steel is not deoxidised properly
C. Decreases the blow holes formation tendency in castings
D. None of these - White cast iron as compared to grey cast iron is ________________?
A. More durable
B. Very brittle
C. Very hard
D. All A., B. & C. - Cast iron is having very high ___________________?
A. Proximity between its elastic limit and ultimate breaking strength
B. Ductility
C. Tensile strength
D. All A., B. and C. - Presence of even very minute amount (say 0.1%) of ______________ in copper, reduces its electrical conductivity very seriously?
A. Bismuth
B. Arsenic
C. Antimony
D. Both B. and C. - Silicon percentage in iron castings to have maximum hardness should be about__________________?
A. 0.3
B. 0.5
C. 0.8
D. 2.5 - With increase in carbide/graphite ratio in cast iron, its__________________?
A. Hardness & brittleness increases
B. Ductility decreases
C. Both A. and B.
D. Neither A. nor B.
