BARC 2020;Manufacturing Nuclear Quiz 1

In a certain ECM operation, the frontal working area of the electrode is 2000 . The applied current and voltage are 1800 A and 12 V respectively. The material being machined is Nickel (Valency 2) whose specific material rate C=3 .42x. The efficiency of the process is 90% and the resistivity of the electrolyte is 140 ohm-mm , with an overvoltage of 1 .5 V. The MRR in and the working gap respectively are:

In orthogonal turning of a cylindrical tube of wall thickness 5 mm, the axial and the tangential cutting forces were measured as 1259 N and 1601 N, respectively. The measured chip thickness after machining was found to be 0.3 mm. The rake angle was 10^o and the axial feed was 100 mm/min. the rotational speed of the spindle was 1000 rpm. Assuming the material to be perfectly and Merchant’s first solution, the shear strength of the material is closest to

A cylindrical work-piece of diameter 10 cm is turned on a lathe in orthogonal cutting condition using a tool of 15^o rake angle. A chip of length 20 cm is obtained while cutting with a depth of cut of 0.6 mm. Then the value of shear plane angle and chip thickness are:

The deformation processes in Column I are to be matched with the corresponding states of stress listed in Column II

The correct match will be :

Match the following List-1 with List-2

List-1

A) full annealing

B) process annealing

C) diffusion annealing

D) spherodise annealing

List-2

1) Stress relieving

2) machinability increases

3) Both ductility and toughness increases

4) to homogenize the chemistry of material

Which of the following is not a line standard?

Errors are generally distributed in accordance with the Gaussian distribution is

A DC arc welding has its voltage-arc length characteristics given by V= 5+10L , where L=arc length in cm. The power source is approximated as a straight line for which the open circuit voltage is 20 V and the short circuit current is 250 A. The optimum arc length is :