Question 1

**PART - A**

Accepted Answer

A thermodynamic system is a specifically defined quantity of matter or a designated region in physical space rigorously chosen for analytical study, while the surroundings completely encompass everything external to this defined system.

Question 2

Q.2 State Zeroth law of thermodynamics.

Accepted Answer

The Zeroth Law of Thermodynamics rigorously states that if two independent systems are each individually in strict thermal equilibrium with a third system, they are absolutely in thermal equilibrium directly with each other.

Question 3

Q.3 Define dryness fraction of steam.

Accepted Answer

The dryness fraction ($x$) mathematically quantifies the exact quality of a liquid-vapor mixture, rigorously defined as the ratio of the mass of actual dry vapor to the total physical mass of the entire mixture.

Question 4

Q.4 Mention the main components of IC engine.

Accepted Answer

The primary structural components of an Internal Combustion (IC) engine rigorously include the cylinder block, reciprocating piston, connecting rod, primary crankshaft, intake/exhaust valves, and the inertial flywheel.

Question 5

Q.5 Define COP of refrigerator.

Accepted Answer

The Coefficient of Performance (COP) mathematically defines the thermodynamic efficiency of a refrigeration cycle, rigorously calculated as the ratio of the desired cooling effect strictly to the external mechanical work required.

Question 6

Q.6 What is priming in centrifugal pump?

Accepted Answer

Priming is the absolutely mandatory operational process of manually filling a centrifugal pump's entire volute casing and suction pipe completely with the working liquid strictly to displace all trapped air before activation.

Question 7

Q.7 Why gear drive is called positive drive?

Accepted Answer

A mechanical gear drive is universally classified strictly as a positive drive because the rigid geometric interlocking of machined gear teeth absolutely prevents any physical slippage during continuous power transmission.

Question 8

Q.8 List four types of patterns used in casting.

Accepted Answer

Four fundamental types of patterns utilized heavily in modern foundry casting processes are the solid (single-piece) pattern, the split (two-piece) pattern, the match-plate pattern, and the large sweep pattern.

Question 9

Q.9 Define welding.

Accepted Answer

Welding is a highly permanent manufacturing fabrication process that systematically joins distinct materials rigorously by generating localized extreme heat to induce complete physical melting and atomic-level fusion at the joint.

Question 10

Q.10 What is 18:4:1 High Speed Steel?

Accepted Answer

The metallurgical designation '18:4:1 steel' specifically identifies a highly optimized grade of High-Speed Steel (HSS) strictly alloyed with exactly 18% Tungsten, 4% Chromium, and 1% Vanadium.

Question 11

**PART - B**

Accepted Answer

The Kelvin-Planck statement explicitly denies the possibility of a 100% efficient heat engine, while the Clausius statement explicitly denies the possibility of spontaneous heat transfer from a colder to a hotter body without external mechanical work.

Question 12

Q.2 Classify boilers. Describe any one fire tube boiler with sketch.

Accepted Answer

A Cochran boiler is a vertical, multi-tubular, internally fired, natural circulation fire-tube boiler engineered explicitly for generating modest quantities of low-pressure industrial steam within highly constrained floor spaces.

Question 13

Q.3 Derive efficiency of Otto cycle.

Accepted Answer

The air-standard mathematical efficiency of the theoretical Otto cycle is rigorously defined by the equation $\eta = 1 - \frac{1}{r^{\gamma-1}}$, where $r$ explicitly represents the geometric volumetric compression ratio and $\gamma$ strictly represents the specific heat ratio of the working fluid.

Question 14

Q.4 Compare 2-stroke and 4-stroke engines.

Accepted Answer

A four-stroke engine executes one complete thermodynamic cycle over four distinct piston strokes and two full mechanical crankshaft revolutions, offering superior thermal efficiency, whereas a two-stroke engine completes the entire cycle in just two strokes and one singular revolution, offering incredibly high power density.

Question 15

Q.5 Differentiate between welding, brazing and soldering.

Accepted Answer

Welding completely melts the base metals for a high-strength atomic bond, brazing utilizes a filler metal melting strictly above $450^{\circ}	ext{C}$ without melting the base metal, and soldering uses a low-melting filler strictly below $450^{\circ}	ext{C}$ for delicate electronic connections.

Question 16

Q.6 Explain V-belt drive and its advantages.

Accepted Answer

V-belts are heavily utilized in mechanical power transmission because their unique trapezoidal cross-section geometrically wedges tightly into grooved pulleys, generating massive frictional grip that strictly prevents slip and permits highly compact, short-center drive designs.

Question 17

Q.7 Explain rolling and extrusion processes.

Accepted Answer

Rolling is a bulk deformation process that aggressively reduces material thickness by squeezing metal directly between massive rotating cylinders, whereas extrusion is a severe shaping process that violently forces a heated metal billet strictly through a shaped die to create continuous, complex cross-sections.

Question 18

**PART - C**

Accepted Answer

A reciprocating pump is a highly robust, positive-displacement machine that fundamentally utilizes a continuous back-and-forth linear motion of a solid plunger or piston within a precisely bored cylinder to forcefully draw in liquid and mechanically discharge it at a significantly elevated pressure.

Question 19

Q.2 Describe Vapour Compression Refrigeration cycle with P-h and T-s diagrams.

Accepted Answer

The Vapor Compression Refrigeration (VCR) cycle is a rigorous thermodynamic process utilizing a circulating volatile refrigerant to continuously extract heat from a low-temperature space via a precise sequence of compression, condensation, expansion, and evaporation.

Question 20

Q.3 A belt is running over a pulley of 600 mm diameter at 200 rpm. The coeffi…

Accepted Answer

By rigorously calculating the exact linear belt velocity and applying the universal flat belt tension ratio formula ($T_1/T_2 = e^{\mu	heta}$), the precise mathematical power transmitted by the mechanical belt drive is definitively evaluated to be $7.89 	ext{ kW}$.

Question 21

Q.4 Explain Oxy-acetylene welding and its types of flames.

Accepted Answer

Oxy-acetylene welding systematically utilizes the extreme thermal combustion of exactly oxygen and acetylene gases to produce three highly distinct, chemically active flame profiles: the Neutral Flame, the Oxidizing Flame, and the Carburizing (Reducing) Flame.

Question 22

Q.5 Write short notes on any two: (a) Forging (b) Engineering Materials (c) C…

Accepted Answer

Forging is a massive thermomechanical deformation process that rigorously shapes solid metal via extreme compressive hammering, drastically improving metallurgical grain structure, while engineering materials are broadly classified to systematically dictate their exact structural, thermal, and mechanical applications.

Basic Mechanical Engineering