A. Bismuth
B. Arsenic
C. Antimony
D. Both B. and C.
Related Mcqs:
- The electrical conductivity of a ______________ decreases with rise in temperature?
A. Metal/alloy
B. Semi-conductor
C. Dielectric
D. None of these - 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 - Presence of even 0.005% of _____________ in copper makes it highly brittle, rendering it useless for wire-drawing?
A. Oxygen
B. Arsenic
C. Antimony
D. Bismuth - Presence of 0.3 to 0.5% arsenic in copper increases its____________________?
A. Ductility
B. Malleability
C. Tenacity & hardness
D. Electrical conductivity - Copper is dissolved from its ore by H2SO4 in a percolation tank made of_________________?
A. Wood
B. Stainless steel
C. Reinforced concrete lined with lead
D. High silicon iron (14% Si) - Presence of high amount of silicon in cast iron________________?
A. Suppresses the decomposition of Fe3C
B. Increases the formation of graphite
C. Increases the contraction of the metal
D. Reduces its fluidity - Reduction in the grain size reduces the _______________ of the material?
A. Fatigue resistance
B. Tensile strength
C. Creep resistance
D. All A., B. & C. - The formation of oxide film on a metal due to atmospheric exposure reduces its____________?
A. Toughness
B. Stiffness
C. Creep limit
D. All A., B. & C. - Amount of energy that a material can absorb before its fracture is a measure of its _________________?
A. Toughness
B. Resilience
C. Malleability
D. Ductility - Bronze is an alloy of copper and _________________?
A. Lead
B. Tin
C. Nickel
D. Zinc
