21851. Which metal is protected by the layer of its own oxide ?
21852. Failure of a material is termed as fatigue failure, if it fails below the yield point. The resistance to fatigue failure of a material is measured by the
21853. Bog iron used for the adsorption of H2S from coke oven gas is
21854. Wrought iron is a suitable material of construction for handling __________ solutions.
21855. Steel rods are used in reinforced concrete to increase its __________ strength.
21856. Corrosion involves exchange of electrons in __________ corrosion.
21857. Straight silicon steel (containing Si from 0.5 to 5%) because of their low hysterisis 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%) ?
21858. To change reciprocating motion to rotary motion,the engine has
21859. __________ does not contain tin as an alloying material.
21860. A metallic alloy in general as compared to their pure metal components is
21861. In the diesel engine,the air is compressed to a little as
21862. When the gear ratio through the transmission is 1:1,the transmission is in
21863. Copper is dissolved from its ore by H2SO4 in a percolation tank made of
21864. Bearings subjected to light load are made of
21865. The least count of a steel rule is
21866. The mechanical speedometer,drive gear mounted on the
21867. Ceramic materials fabrication can not be done by
21868. Which has the maximum melting point out of the following ?
21869. Cast iron is
21870. Which of the following has no effect on the carbide forming tendency in steels ?
21871. Approximate value of the modulus of elasticity for steel is about __________ x l06kg/cm2.
21872. Carbon is present in steel wholly in the
21873. Which test is conducted to know the chemical condition of the plate of a lead acid battery?
21874. In SO3 absorber (Contact Process), packing material used is of
21875. Presence of manganese in alloy steel improves its
21876. Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with
21877. A material is called 'ductile', if it can be
21878. A chemical change takes place when iron
21879. Evaporator used for concentrating tomato juice is made of
21880. High carbon steel contains more than __________ percent carbon.
21881. The main constituent of carborundum is __________ carbide.
21882. For storing water and acid free benzol, use a __________ vessel.
21883. The chlorinator used in the manufacture of DDT is made of
21884. Another name of formula wheel is known as
21885. Age hardening is concerned with
21886. Which of the following undergoes granular fracture ?
21887. Ball bearings are normally made of __________ steel.
21888. The electrical conductivity of a __________ decreases with rise in temperature.
21889. Which one occupies the lowermost position in the electromotive series of metals ?
21890. Addition of nickel to copper improves its
21891. Presence of even 0.005% of __________ in copper makes it highly brittle, rendering it useless for wire-drawing.
21892. High speed cutting tool steels contain about __________ percent of tungsten.
21893. The 'bomb' in the bomb calorimeter is made of
21894. Which of the following is produced by condensation polymerisation ?
21895. The crystal structure of most of the common metals is
21896. Telfon (PTFE) is corroded by
21897. Hastelloy C is a good material of construction in chemical process industry, since it is
21898. Mixing vessel used for the chlorination of methane to produce methyl chloride is made of
21899. The loss of strength in compression which occurs, when there is a gain of strength in tension due to over loading is called