In the context of tensile test of a ductile alloy, the following observations were made. Choose the correct ones from the following observations:
P. Per cent elongation is independent of the dimensions of the test specimens.
Q. The number of necking instabilities are different in cylindrical and sheet specimens.
R. The range of strain rates to be used for 'static tensile test' is 10^-1 to 10^-5 s^-1.
R. The yield stress is independent of the temperature of the test.

Fatigue life is expected to increase by

A. increasing the size of the sample

B. smooth polishing of the surface of the sample

C. having compressive residual stresses at the surface

D. having tensile residual stresses at the surface

Which of the following is a function of a developer

A. Providing a contrasting background for visible dye indications

B. Making the penetrant water washable

C. Penetrating into discontinuities open to the surface

D. Dissolve organic soils on the test piece surface

With an increase in temperature, hardness of material . . . . . . . . and ductility . . . . . . . .

A. Increases, increases

B. Increases, decreases

C. Decreases, increases

D. Decreases, decreases

A brale indentor used in Rockwell hardness test has the following geometry and material.

A. Square based diamond pyramid with 136° included angle

B. Conical shape steel with 120° apex angle

C. Conical shaped diamond with 120° apex angle

D. 10 mm diameter hardened steel ball