Question 1

**PART-A**

Accepted Answer

The Zeroth Law of Thermodynamics establishes the foundational concept of temperature measurement and thermal equilibrium between interacting systems.

Question 2

Q.2. Discuss the two important properties of Steam.

Accepted Answer

Pressure and Temperature are two vital intensive thermodynamic properties that dictate the phase, specific volume, and enthalpy of steam.

Question 3

Q.3. What are the main components of IC engine?

Accepted Answer

The principal structural and moving components of an IC engine include the Engine Cylinder, Piston, Connecting Rod, and Crankshaft.

Question 4

Q.4. What is meant by priming in centrifugal pumps?

Accepted Answer

Priming is the mandatory preparatory process of completely filling the suction pipe and pump casing with liquid before starting.

Question 5

Q.5. Define the performance measure of a refrigerator and a heat pump.

Accepted Answer

The performance of refrigerators and heat pumps is quantified by the Coefficient of Performance (COP), comparing desired output to work input.

Question 6

Q.6. Why gear drive is called as positive drive?

Accepted Answer

A gear drive is classified as a 'positive drive' because it transmits motion without any slippage due to interlocking teeth.

Question 7

Q.7. List the different fields of mechanical engineering.

Accepted Answer

Mechanical engineering is a vast discipline encompassing Thermal Engineering, Manufacturing Technology, Machine Design, and Industrial Management.

Question 8

Q.8. What is the difference between open belt and cross belt?

Accepted Answer

Open belt drives rotate shafts in the same direction, while cross belt drives reverse the direction of rotation.

Question 9

Q.9. Give the name of four types of patterns.

Accepted Answer

Four common types of patterns used in sand casting include Solid, Split, Match Plate, and Sweep patterns.

Question 10

Q.10. What is 18:4:1 steel? State its application.

Accepted Answer

18:4:1 steel represents a standard High-Speed Steel (HSS) alloy composition, crucial for maintaining hardness at extreme cutting temperatures.

Question 11

**PART-B**

Accepted Answer

The Second Law of Thermodynamics dictates the direction of heat transfer and limits the thermal efficiency of heat engines. A heat engine cannot operate without rejecting waste heat, as stated by the Kelvin-Planck statement.

Question 12

Q.2. Discuss the classification of the Steam Boilers. Explain the working of …

Accepted Answer

Steam boilers are broadly classified into Fire-Tube and Water-Tube types. A Babcock & Wilcox boiler is a prominent water-tube boiler designed for high pressure.

Question 13

Q.3. Derive an expression for the air standard efficiency of Otto cycle. Draw…

Accepted Answer

The Otto cycle forms the thermodynamic basis for spark-ignition petrol engines. Its efficiency depends solely on the compression ratio and the specific heat ratio of the working fluid.

Question 14

Q.4. Differentiate among the welding, brazing and soldering.

Accepted Answer

Welding, brazing, and soldering are distinct joining processes varying by temperature, filler material, and whether the base metal itself is melted.

Question 15

Q.5. Compare the working of two stroke and four stroke Internal Combustion En…

Accepted Answer

Four-stroke engines separate intake, compression, power, and exhaust into four distinct piston movements, yielding high efficiency. Two-stroke engines combine these into two movements for high power density.

Question 16

Q.6. Derive an expression for the ratio of tensions in a V-belt drive.

Accepted Answer

The tension ratio for a V-belt drive is T1/T2 = e^(μθ / sin α), demonstrating that the wedge effect dramatically increases gripping friction compared to a flat belt.

Question 17

Q.7. Discuss the following manufacturing processes: (a) Rolling (b) Extrusion

Accepted Answer

Rolling deforms metal between massive rotating cylinders to reduce thickness, while extrusion forces heated metal through a die to create long, complex continuous profiles.

Question 18

**PART-C**

Accepted Answer

Oxy-acetylene welding uses a combustible gas flame for versatile metal joining, whereas metal arc welding utilizes an intense electrical arc to melt consumable electrodes for heavy-duty structural fabrication.

Question 19

Q.2. Explain the working of a reciprocating pump with neat sketch.

Accepted Answer

A reciprocating pump is a robust positive displacement device that uses the alternating motion of a piston within a cylinder, coordinated with check valves, to physically forcefully push liquid to extremely high pressures.

Question 20

Q.3. Find the power transmitted by a belt running over a pulley of 500 mm dia…

Accepted Answer

Using the principles of belt friction and rotational kinematics, the power transmitted by the belt drive is calculated to be approximately 8.95 kW.

Question 21

Q.4. Explain the following: (a) Vapour compression refrigeration cycle (b) Co…

Accepted Answer

The Vapour Compression Refrigeration (VCR) cycle leverages phase changes of a volatile refrigerant to extract heat, while comfort air conditioning actively manages air properties for human physiological well-being.

Question 22

Q.5. Write a short note on any two of the following: (a) Classification of IC…

Accepted Answer

IC engines are categorized by ignition methods or cycles. Forging is a high-strength compressive forming process. Engineering materials span metals, polymers, and ceramics with distinct properties.

Basic Mechanical Engineering