GATE Mechanical Practice Test

1. The ignition quality of diesel fuel is indicated by

Octane number

Cetane number

Flash point

Fire point

2. Cold working of metals of metals increases

Tensile strength

Hardness

Yield strength

All of these

3. A streamline and an equipotential line in a flow field

Are parallel to each other

Are perpendicular to each other

Intersect at an acute angle

Are identical

4. The compression ratio of an SI engine is in the range of

4 to 6

6 to 10

6 to 8

10 to 14

In case of SI engine the ignition occur due to spark so compression ratio relatively low about 6 to 10

Explanation

In case of SI engine the ignition occur due to spark so compression ratio relatively low about 6 to 10

5. When air is adiabatically saturated, the temperature attained is

Dew point temperature

Wet bulb temperature

Dry bulb temperature

Triple point temperature

In adiabatic process wet bulb temp remain constant

Explanation

In adiabatic process wet bulb temp remain constant

6. The alloying elements mainly used to improve the endurance strength of steel material is

Nickle

Vanadium

Molybdenum

Tungsten

7. Cast steel is crankshaft is hardened by

Nitriding

Normalising

Carburising

Induction heating

8. The moving mandrel is used in

Tube drawing

Wire drawing

Extrusion

Spinning

9. In metals subjected to cold working, strain hardening effect due to

Slip mechanism

Twinning mechanism

Dislocation mechanism

Fracture mechanism