Mock paper for campus placement 5

Mock campus paper for mechanical 5

1. Superheated vapour behaves
(a) exactly as gas (b) as steam (c) as ordinary vapour (d) approximately as gas

2. No liquid can exist as liquid at
(a) vaccum (b) zero pressure (c) centre of earth (d) in space

3. The behaviour of gases can be fully determined by
(a) 1 law (b) 2 laws (c) 3 laws (d) 4 laws

4. Heat and work are
(a) point function (b) system properties (c) path function (d) intensive properties

5. Change in enthalpy of a system is the heat supplied at
(a) constant pressure (b) constant temperature (c) constant volume (d) constant
entropy

6. Which of the following parameters remains constant during ideal throttling process
(a) pressure (b) temperature (c) volume (d) enthalpy

7. In case of refrigeration machine, COP will be equal to
(a) Q2/(Q1-Q2) (b) Q1/(Q1-Q2) (c) (Q1-Q2)/Q1 (d) (Q2-Q1)/Q1

8. If hot water and cold water are mixed, then the entropy of the system will
(a) increase (b) decrease (c) remain same (d) attain negative value

9. A process occur spontaneously if its entropy
(a) increases (b) decreases (c) remain same (d) becomes zero

10. Triple point of a pure substance is a point at which
(a) liquid and vapour exist together (b) solid and liquid exist together
(c) solid and vapour exist together (d) solid. Liquid and vapour phases exist together

11.Small percentage of boron is added to steel to
a) increase hardenability (b)reduce machinability (c)increase wear resistance
d)increase endurance strength

12.. Killed steels
a) have minimum impurity level b) have almost zero percentage of phosphorous and sulphur
c) are produced by LD process d) are free from oxygen

13.. In low carbon steels, presence of small quantities sulphur improves
a) weldability (b)formability (c)machinability (d)hardenability

14.. Which one of the following sets of constituents is expected in equilibrium cooling of a hypereutectoid steel from austenitic steel?
a) Ferrite and pearlite b) Cementite and peralite c) Ferrite and bainite d) Cementite and martensite

15.. Guideways of Lathe bed are hardened by
a) carburizing b) cyaniding c) nitriding d) flame hardening

16.The main aim of compounding of steam turbine is to
a) improve efficiency b)reduce steam consumption c)reduce motor speed d)reduce turbine size

17. Heat conduction does not occur
a) If a physical body is impermeable to any kind of rays
b) If the parts of a body are not in motion relative to one another
c) If the bodies are kept in vacuum d) If the temperature difference between the bodies does not exist

18. Which is not the assumption of Fourier’s equation of heat conduction?
a) Homogeneous substance b) Steady heat flow c) Constant temperature difference
d) Uniform area of cross section

19. Three rods one made of glass, one of pure aluminium and one made of wrought iron are heated to 150˚ C. All the rods are 15 mm in diameter and 300 mm long. The lowest temperature at the free end of the rods will occur in case of
a) Aluminium rod b) Wrought iron c) Glass rod d) Temperature will be same for all the three rods at free end

20. Non dimensional number generally involved in case of heat transfer from horizontal cylinder by natural convection is
a) Grashof’s number b) Nusselt number c) Prandtl number d) All of these

21. A slab of ice has one – half covered with black cloth and the other half with white cloth. The slab is now placed in sunlight. It will be observed that
a) more ice will melt under black cloth b) more ice will melt under white cloth
c) equal amount of ice will melt under the two cloths d) ice will not melt

22. In heat exchanger design, one transfer unit means
a) One fluid exchanging with another fluid of the same chemical compostion
b) The section of heat exchanger which will cause temperature drop of one degree centigrade
c) The section of heat exchanger where heat exchanger where heat transfer surface area is one square metre
d) Condition when the change in temperature of 1˚ C numerically equals the average driving force

23. A liquid to liquid counterflow heat exchanger is used to heat cold fluid from 50˚ C to 150˚ C. Assuming that the hot fluid enters at 250˚ C and leaves at 200˚ C, the log mean temperature difference for the heat exchanger will be closer to
a) 100˚ C b) 128˚ C c) 133˚ C d) 137˚ C

24. A wall has two layers A and B, each made of a different material. Both the layers have the same thickness. The thermal conductivity of material of A is twice that of B. Under the thermal equilibrium the temperature difference across the wall is 30˚ C. The temperature drops in layers A and B will be respectively
a) 20˚ C and 10˚ C b) 10˚ C and 20˚ C c) 15˚ C and 15˚ C d) cannot be predicted

25. Which of the following is a lower pair?
a) Piston and cylinder b) Cam and follower c) Belt drive d) Gear