When vapour is cooled at constant total system volume, the _______ changes.

Consider the following statements and choose the correct answer:
1. A direct proportionality exists between vapour pressure and the concentration of water vapour in the atmosphere
2. Relative humidity is an expression of the ratio of the actual vapour pressure of the atmosphere when saturated at the same temperature
3. A rise or fall in temperature with no change in vapour pressure will cause a drop or rise, respectively, in relative humidity
4. A rise or fall in vapour pressure with no change in temperature will be accompanied by a rise or fall, respectively, in relative humidity

A

1, 2, 3 and 4 are true

B

Only 3 and 4 are true

C

Only 2 and 4 are true

D

Only 1, 2 and 3 are true

Statement (I): Piston temperature profiles near full load are flattened in case of liquid cooled engines whereas for air cooled engines temperature profiles are steeper. Statement (II): The piston temperature profiles are different in nature for liquid cooled and air cooled engines because of the different values of heat capacities.

A

Both Statement I) and Statement II) are individually true and Statement II) is the correct explanation of Statement I)

B

Both Statement I) and Statement II) are individually true but Statement II) is not the correct explanation of Statement I)

C

Statement I) is true but Statement II) is false

D

Statement I) is false but Statement II) is true

Group I shows different heat addition processes in power cycles. Likewise, Group II shows different heat removal processes. Group III lists power cycles. Match items from Groups I, II and III. Group I Group II Group III P. Pressure constant S. Pressure constant 1. Rankine cycle Q. Volume constant T. Volume constant 2. Otto cycle R. Temperature constant U. Temperature constant 3. Carnot cycle 4. Diesel cycle 5. Brayton cycle

A

P – S – 5, R – U – 3, P – S – 1, Q – T - 2

B

P – S – 1, R – U – 3, P – S – 4, P – T - 2

C

R – T – 3, P – S – 1, P – T – 4, Q – S - 5

D

P – T – 4, R – S – 3, P – S – 1, P – S - 5

Two involute gears are designed to mesh for a given centre distance and a given angular velocity ratio (other than 1). During assembly, the centre distance has increased slightly. Then which of the following changes occur? (i) Velocity ratio changes (ii) Pressure angle changes (iii) Pitch circle diameter changes (iv) Working depth changes (v) Base circle radius changes Select the correct answer using the code given below.

A

1, 2 and 3

B

2, 3 and 4

C

2 and 5

D

3 and 5

A database of research articles in a journal uses the following schema. (VOLUME, NUMBER, STARTPAGE, ENDPAGE, TITLE, YEAR, PRICE) The primary key is (VOLUME, NUMBER, STARTPAGE, ENDPAGE) and the following functional dependencies exist in the schema. (VOLUME, NUMBER, STARTPAGE, ENDPAGE) → TITLE (VOLUME, NUMBER) → YEAR (VOLUME, NUMBER, STARTPAGE, ENDPAGE) → PRICE The database is redesigned to use the following schemas. (VOLUME, NUMBER, STARTPAGE, ENDPAGE, TITLE, PRICE) (VOLUME, NUMBER, YEAR) Which is the weakest normal form that the new database satisfies, but the old one does not?

A

1NF

B

2NF

C

3NF

D

BCNF

A vessel of volume 1000 m³ contains air which is saturated with water vapour. The total pressure and temperature are 100 kPa and 20°C respectively. Assuming that the vapour pressure of water at 20°C is 2.34 kPa, the amount of water vapour (in kg) in the vessel is approximately

A

17

B

20

C

25

D

34

Consider the following statements: 1. There is no change in temperature when a liquid is being evaporated into vapour 2. Vapour is a mixed phase of liquid and gas in the zone between saturated liquid line and saturated vapour line 3. The saturated dry vapour curve is steeper as compared to saturated liquid curve on a T-s diagram 4. The enthalpy of vaporization decreases with increase in pressure Which of the above statements are correct?

A

1, 2 and 3 only

B

3 and 4 only

C

1, 2 and 4 only

D

1, 2, 3 and 4

A cylinder contains 1kg of ammonia. Initially the ammonia is at 180°C, 2 MPa and is now cooled to saturated vapour at 40°C, and then further cooled to 20°C, at which point the quality is 50%. Find the total work for the process, assuming a linear variation of P versus V.

A

-19.4 kJ

B

-29.4 kJ

C

-39.4 kJ

D

-49.4 kJ

Mundel's classes of change includes
1. Changes in body motions and positions
2. Changes in equipment and working arrangements
3. Changes in production sequence
4. Changes in finished product
5. Changes in raw material

A

1, 2 and 3

B

1, 2, 3 and 4

C

1, 2, 3, 4 and 5

D

None of these

When a mixture of air and water vapour is cooled at constant pressure upto saturation temperature of water vapour, the temperature attained is known as:

A

Dry bulb temperature

B

Wet bulb temperature

C

Dew point temperature

D

Critical temperature

When vapour is cooled at constant total system volume, the _______ changes.

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