Elinvar, an alloy used in precision instruments, hair springs for watches, etc. contains the following element as principal alloying element__________________?
(A) iron
(B) copper
(C) aluminium
(D) zinc
(D) nickel
Addition of lead and bismuth to aluminium results in_________________?
(A) improvement of casting characteristics
(B) improvement of corrosion resistance
(C) one of the best known age and precipitation-hardening systems
(D) improving machinability
(D) none of the above
Constantant an alloy used in thermocouples is an alloy of __________________?
(A) copper and tin
(B) copper and zinc
(C) copper and iron
(D) copper and nickel
(D) copper and chromium
Specific weight of water in S.I. units is equal to ________________?
(A) 1000 N/m3
(B) 10000 N/m3
(C) 9.81 xlO3 N/m3
(D) 9.81 xlO6N/m3
(D) 9.81 N/m3
Mercury does not wet glass. This is due to property of liquid known as__________________?
(A) adhesion
(B) cohesion
(C) surface tension
(D) viscosity
(D) compressibility
The value of mass density in kgsecVm4 for water at 0°C is_________________?
(A) 1
(B) 1000
(C) 100
(D) 101.9
(D) 91
Liquids_________________?
(A) cannot be compressed
(B) occupy definite volume
(C) are not affected by change in pressure and temperature
(D) are not viscous
(D) none of the above
An ideal flow of any fluid must fulfill the following____________________?
(A) Newton’s law of motion
(B) Newton’s law of viscosity
(C) Pascal’ law
(D) Continuity equation
(D) Boundary layer theory
In a static fluid ___________________?
(A) resistance to shear stress is small
(B) fluid pressure is zero
(C) linear deformation is small
(D) only normal stresses can exist
(D) viscosity is nil
Bell metal contains_____________________?
(A) 70% copper and 30% zinc
(B) 90% copper and 10% tin
(C) 85-92% copper and rest tin with little lead and nickel
(D) 70-75% copper and rest tin
(D) 70-75% copper and rest zinc and tin