DMRC JE Previous Year Questions Solved | DMRC JE 2018 Mechanical Preparation -Part 2

DMRC JE Previous Year Questions Solved PART 2

1. An orthogonal cutting operation is being carried out under the following conditions Cutting speed (V)=2m/s, depth of cut=0.5 mm, chip thickness=0.6mm Then chip velocity is:

(1) 2 m/s (2) 1.66 m/s

(3) 1 m/s (4) None of these

2. A 40 mm diameter rod is to be turned on a lathe at a cutting speed of 30 m/min. The required spindle speed should be approximately:

(1) 120 rpm (2) 180 rpm

(3) 240 rpm (4) None of these

3. The electric resistance welding operates with:

(1) Low current and high voltage

(2) High current and low voltage

(3) Low current and low voltage

(4) High current and high voltage

4. A tank containing air is stirred by a paddle wheel. The work input to the paddle wheel is 9000 KJ and heat transferred to the surroundings from the tank is 3000 KJ. The external work done by the system is:

(1) Zero (2) 3000 KJ

(3) 6000 KJ (4) None of these

5. If the thermal efficiency of a Carnot heat engine is 40%, then Co-efficient of the performance of a refrigerator working within same temperature limits would be:

(1) 4.5 (2) 3.5

(3) 1.5 (4) None of these

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