In case of brasses, with decreasing zinc percentage and increasing copper percentage, its _____________ increases ?
(A) Percentage elongation
(B) Brinell hardness
(C) Tensile strength
(D) All A, B & C
Limestone addition in the blast furnace is done to flux _______________ present in the raw materials?
(A) SiO2
(B) Al2O3
(C) MnO2
(D) P
Normalising of a casting does not__________________?
(A) Induce stresses in it
(B) Refine its grain structure
(C) Reduce segregation
(D) Improve its mechanical properties
Lead is poured into the joint between two ______________ pipes?
(A) Mild steel
(B) Concrete
(C) Cast iron
(D) Asbestos cement
The emf of a Deniell cell “Zn | Zn2+ || Cu2+ | Cu” can be increased by_________________?
(A) Decreasing the surface area of the electrodes
(B) Increasing the concentration of zinc sulphate solution
(C) Increasing the surface area of the electrodes
(D) Increasing the concentration of copper sulphate solution
Which of the following materials does not form adherent oxide film on surface ?
(A) Copper
(B) Nickel
(C) Aluminium
(D) Gold & silver
In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be_______________?
(A) ΔQ = 0, ΔS=0
(B) ΔQ = 0, ΔS = +ve
(C) ΔQ = 0, ΔS = -ve
(D) ΔQ = +ve, ΔS= +ve
The most suitable material for die casting is __________________?
(A) Iron
(B) Copper
(C) Steel
(D) Nickel
The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : Cp of copper is 23 J K-1mole-1) ?
(A) 2300 J
(B) 4600 J
(C) 230 J
(D) 2.3 × 106 J
______________ wire is never used for making the heating element ?
(A) Nichrome
(B) Kanthal
(C) Invar
(D) None of these