Q: Definition check: What qualifies as a convergent nozzle in fluid/steam-nozzle terminology? Identify the correct description of how the cross-sectional area changes from inlet to exit. Choose the correct option.

Given Question asks for the definition of a convergent nozzle. Concept A convergent nozzle has a monotonically decreasing flow area from the inlet to the exit; a convergent–divergent (C–D) nozzle has a minimum area (throat) followed by a diverging exit section. Final Answer Area decreases continuously from entrance to exit.

Q: True/False (steam nozzles): Compare critical pressure ratios for different steam qualities. Statement: “The critical pressure ratio for initially dry saturated steam is greater than that for initially wet steam.” Decide whether the statement is cor…

Concept Critical pressure ratio (p₂/p₁) for choking depends on the effective expansion index and thermodynamic properties of the working fluid. With higher dryness fraction (approaching dry saturated), the effective index yields a slightly higher critical pressure ratio than for wetter steam. Implication Thus, for the same inlet state, initially dry saturated steam requires a relatively higher p₂/p₁ to choke than initially wet steam. Final Answer Agree.

Question 1

Supersaturated steam flow through a nozzle vs. stable (equilibrium) flow  When steam expands with supersaturation (delayed condensation), how does the available heat drop compare to a stable (equilibrium) expansion? Choose the correct option.

Accepted Answer

Concept Supersaturation delays condensation, so steam expands further in a metastable state before nuclei form. This permits a larger effective pressure/enthalpy drop across the nozzle prior to condensation (commonly evidenced by slightly higher exit velocity and mass flow than the equilibrium prediction). Implication Because of delayed phase change, the available heat drop (and thus attainable jet kinetic energy) tends to be higher than under fully stable equilibrium expansion at the same inlet and back pressures. Final Answer Increases

Question 2

Applications of steam turbines  Identify where steam turbines are commonly used in practice. Choose the correct option.

Accepted Answer

Concept Steam turbines are versatile prime movers used in marine propulsion (especially large ships), power plants (utility and industrial), and for mechanical drives (fans, compressors, pumps) where high-speed, continuous-duty operation is needed. Final Answer All of these

Question 3

Type classification: De Laval turbine  Classify the De Laval turbine according to type and staging. Choose the correct option.

Accepted Answer

Concept The classic De Laval machine is a single-stage, single-rotor impulse turbine with a convergent–divergent nozzle and one ring of moving blades. All pressure drop occurs in the nozzle; the rotor extracts kinetic energy only. Final Answer Single-rotor impulse turbine

Question 4

Exit state from a nozzle  Steam leaves a nozzle with what typical combination of pressure and velocity? Choose the correct option.

Accepted Answer

Concept A nozzle converts pressure energy into kinetic energy: pressure drops while velocity rises. Therefore, the exit condition is low pressure, high velocity. Final Answer Low pressure and high velocity

Question 5

Parsons turbine: impulse or reaction?  Identify the correct classification of a Parsons turbine stage. Choose the correct option.

Accepted Answer

Concept The Parsons turbine uses roughly 50% reaction per stage; pressure drop is shared between fixed and moving blades. Hence it is an impulse–reaction type. Final Answer Impulse–reaction turbine

Question 6

Choked flow in a convergent–divergent steam nozzle  Statement: In a C–D nozzle, the mass discharge rate depends on the initial (inlet) steam conditions and the throat area (once choked), not on the exit pressure. Decide whether the statement is corr…

Accepted Answer

Concept After the back pressure is reduced to the critical (choked) value, the throat Mach number is 1. The mass flow then becomes a function of inlet state and throat area only; further reduction of exit pressure does not increase discharge. Final Answer True

Question 7

Effect of reducing back (exit) pressure on nozzle mass flow  As the exit/back pressure is gradually reduced from high to low values, how does the mass discharge rate through a steam nozzle change? Choose the correct option.

Accepted Answer

Concept Before choking, lowering the back pressure increases the pressure drop and hence the mass flow. At the critical back pressure, the flow chokes (Mach 1 at the throat). Beyond this point, further back-pressure reduction cannot raise the mass flow; it stays constant. Graphical view Discharge vs. back pressure: rising curve up to the critical point, then a horizontal plateau. Final Answer Increases up to a critical back pressure and then remains constant

Question 8

Steam nozzle back pressure vs design exit pressure: identify the nozzle condition for expansion.  Given: Back pressure (ambient) is lower than the designed exit pressure of the nozzle. Choose the correct technical term that describes the nozzle cond…

Accepted Answer

Concept/Approach For a fixed-geometry convergent–divergent nozzle, the designed exit pressure is the ambient pressure at which the nozzle ideally expands the fluid to match the surroundings.If the actual back (ambient) pressure is lower than this designed value, the nozzle has not expanded enough — the exit pressure remains higher than ambient — and therefore the jet needs further expansion outside the nozzle. Definition Underexpanded nozzle: exit static pressure > ambient (back) pressure; needs additional expansion externally (expansion fans form at the lip).Overexpanded nozzle: exit static pressure < ambient pressure; external compression shocks form. Final Answer Underexpanded nozzle.

Question 9

Definition check: What qualifies as a convergent nozzle in fluid/steam-nozzle terminology?  Identify the correct description of how the cross-sectional area changes from inlet to exit. Choose the correct option.

Accepted Answer

Given Question asks for the definition of a convergent nozzle. Concept A convergent nozzle has a monotonically decreasing flow area from the inlet to the exit; a convergent–divergent (C–D) nozzle has a minimum area (throat) followed by a diverging exit section. Final Answer Area decreases continuously from entrance to exit.

Question 10

True/False (steam nozzles): Compare critical pressure ratios for different steam qualities.  Statement: “The critical pressure ratio for initially dry saturated steam is greater than that for initially wet steam.” Decide whether the statement is cor…

Accepted Answer

Concept Critical pressure ratio (p₂/p₁) for choking depends on the effective expansion index and thermodynamic properties of the working fluid. With higher dryness fraction (approaching dry saturated), the effective index yields a slightly higher critical pressure ratio than for wetter steam. Implication Thus, for the same inlet state, initially dry saturated steam requires a relatively higher p₂/p₁ to choke than initially wet steam. Final Answer Agree.

Question 11

Steam Turbine Classification – What Defines a Reaction Turbine? In a reaction steam turbine stage, how and where does the steam expand, and what distinguishes it from a pure impulse stage in terms of pressure drop and blade function?

Accepted Answer

Introduction / Context: Steam turbines are broadly categorized as impulse or reaction. Understanding where the pressure drop occurs is fundamental to velocity triangles, stage efficiency, and blade design. This question asks you to identify the hallmark of a reaction stage. Given Data / Assumptions: Single turbine stage with fixed and moving blade rows. Quasi-steady flow and negligible leakage in the ideal description. Steam properties change according to expansion through blade passages. Concept / Approach: In a pure impulse stage (e.g., De Laval), nearly all pressure drop occurs in stationary nozzles, converting pressure energy to kinetic energy; the moving blades ideally only turn the jet with negligible pressure change. In a reaction stage (e.g., Parsons), pressure drops occur in both the fixed and moving passages; both act as nozzles to some degree, and static enthalpy decreases across the rotor as well as the stator. The degree of reaction quantifies the fraction of enthalpy drop in the rotor. Step-by-Step Solution: Define reaction: fraction of stage enthalpy drop occurring in the rotor.Note that both fixed and moving blades have converging passages that accelerate and expand steam.Therefore, pressure drop is shared between stator and rotor.Select the option describing expansion in both blade rows. Verification / Alternative check: Velocity triangles for Parsons stages show changing absolute and relative velocities consistent with pressure reduction across the rotor. Measured pressure taps confirm a drop across both blade rows in reaction stages. Why Other Options Are Wrong: Options (a) and (c) describe impulse operation; (d) is false because pressure and temperature do not remain constant; (e) incorrectly asserts no rotor pressure change, which again matches impulse, not reaction. Common Pitfalls: Assuming all turbines are either 100% impulse or 100% reaction—most practical stages have a degree of reaction between 0 and 1. Final Answer: The expansion of steam occurs partly in fixed (stator) blades and partly in moving (rotor) blades

Question 12

Choked-Flow Threshold – Critical Pressure Ratio for Ideal Gases (Gamma ≈ 1.4) For an ideal gas with specific heat ratio around gamma = 1.4 (e.g., air), the critical pressure ratio (downstream-to-upstream static pressure at sonic throat) is approxima…

Accepted Answer

Introduction / Context: In nozzles and compressible-duct flows, choked flow occurs when the Mach number at the minimum area (throat) reaches 1. The pressure ratio at which this happens is critical for sizing nozzles, valves, and gas-discharging systems. Engineers often memorize an approximate value for air (gamma ≈ 1.4). Given Data / Assumptions: Ideal-gas behavior with constant specific heats. Isentropic, one-dimensional flow through a smoothly contoured nozzle. Upstream reservoir conditions well defined; throat is the minimum area. Concept / Approach: The isentropic relation linking static pressure and Mach number yields the critical pressure ratio at M = 1 as p*/p0 = (2/(gamma + 1))^(gamma/(gamma − 1)). For gamma = 1.4, this evaluates numerically to about 0.528. If the downstream static pressure falls below p* = 0.528 * p0, the mass flow rate remains fixed (choked) and further reductions in back pressure do not increase mass flow. Step-by-Step Solution: Write critical ratio: (p*/p0) = (2/(gamma + 1))^(gamma/(gamma − 1)).Substitute gamma = 1.4 → (2/2.4)^(1.4/0.4).Compute exponent: 1.4/0.4 = 3.5; base ≈ 0.83333.Evaluate numerically → ≈ 0.528 (memorized engineering value). Verification / Alternative check: Design charts and gas-dynamics tables list 0.528 for air. CFD and experiments corroborate that choking begins near this ratio for gamma ≈ 1.4 in smooth nozzles without significant losses. Why Other Options Are Wrong: Values 0.546, 0.577, and 0.582 are off the theoretical value for gamma = 1.4. The slight differences might correspond to different gamma values or non-isentropic effects but are not the standard air value. Common Pitfalls: Confusing p*/p0 with p0/p* (the inverse); forgetting that gamma changes with temperature, slightly shifting the ratio. Also, mixing total (stagnation) vs. static pressures. Final Answer: 0.528

Question 13

Sonic Condition at the Nozzle Throat – Compare with Speed of Sound In steady, isentropic nozzle flow of a compressible fluid, the flow becomes choked at the minimum area. At this choked condition, the fluid velocity at the throat equals, is less tha…

Accepted Answer

Introduction / Context: Choking in compressible flow marks the transition to a sonic condition that caps the mass flow rate for given upstream stagnation conditions. This principle is central to nozzle design, gas safety valves, and rocket propulsion. The question asks what the throat velocity equals at the onset of choking. Given Data / Assumptions: One-dimensional, steady, isentropic flow in a converging (or converging–diverging) nozzle. Well-defined upstream stagnation (total) pressure and temperature. Throat is the minimum cross-sectional area. Concept / Approach: At the critical (choked) condition, the Mach number at the throat is M* = 1. By definition, Mach number M = V/a, where V is the local flow speed and a is the local speed of sound. Therefore, M* = 1 implies V_throat = a_throat. Downstream of the throat in a diverging section, the flow can accelerate to supersonic speeds (M > 1) if the back pressure permits; upstream of the throat in a purely converging nozzle, the flow remains subsonic (M < 1). Step-by-Step Solution: Define Mach number: M = V/a.At choked condition, M_throat = 1.Therefore V_throat = a_throat (equals local speed of sound).Conclude the correct comparison is 'equal to' the speed of sound. Verification / Alternative check: Area–Mach relations show that the minimum-area location corresponds to M = 1 for isentropic flow. Experimental Schlieren images and pitot-static measurements confirm sonic condition at the throat when choked. Why Other Options Are Wrong: 'Less than' describes subsonic pre-throat regions; 'more than' describes supersonic, which occurs only downstream in a diverging section after choking is established. 'Indeterminate' is incorrect because the sonic condition follows from isentropic nozzle theory; 'zero due to vena contracta' confuses internal flow contraction with compressible nozzle throat behavior. Common Pitfalls: Mixing local speed of sound with upstream value; forgetting that sonic condition is local (depends on local temperature). Also, conflating choking with shock formation—shocks may occur downstream but are not required at the throat. Final Answer: equal to

Question 14

Steam turbines — Understanding the reheat factor In multi-stage steam turbines, the reheat factor (often denoted as RF) quantifies how the cumulative actual heat drop across all stages compares with the ideal isentropic heat drop between the same in…

Accepted Answer

Introduction / Context: The reheat factor is a key performance indicator for multi-stage steam turbines. It accounts for the fact that, due to irreversibilities and changing specific volume, the total (cumulative) enthalpy drop actually realized across many stages can differ from the single shot isentropic drop between inlet and outlet states. Understanding what drives the reheat factor helps engineers predict real turbine work and stage loading more accurately. Given Data / Assumptions: Multi-stage impulse or reaction steam turbine. Defined inlet state (pressure, temperature/superheat) and exhaust pressure. Non-ideal effects in each stage (efficiency < 100%). Concept / Approach: Reheat factor RF is defined as the ratio of the cumulative heat drop (sum over stages of actual enthalpy drops realized in blades/nozzles) to the ideal isentropic heat drop between the overall turbine inlet and exit states. Because specific volume increases down the expansion and stage losses vary with operating point, RF reflects how the expansion is distributed and how efficiently each stage converts enthalpy into kinetic work. Step-by-Step Solution: Recognize that higher inlet superheat and pressure influence the initial density and Mach-number regime, altering stage incidence and loss behavior.Identify that lower exhaust pressure (deep vacuum) increases the expansion range and magnifies volumetric flow, changing stage loading and cumulative heat drop.Acknowledge that per-stage efficiency (nozzle, blade, mechanical) directly shapes the realized enthalpy drop per stage; their aggregate sets the cumulative drop.Therefore, RF depends on inlet condition (initial pressure and superheat), exhaust pressure, and stage efficiencies. Verification / Alternative check: Design studies show RF typically exceeds unity slightly (e.g., 1.02–1.07) for many practical turbines because increasing specific volume down the expansion can yield a cumulative drop marginally greater than the single isentropic drop, when summed with realistic stage characteristics. Why Other Options Are Wrong: Picking any single factor (A, B, or C) ignores the coupled nature of expansion: inlet, outlet, and stage performance together determine RF. Common Pitfalls: Confusing “reheat factor” with “reheat cycle.” RF exists even in non-reheated turbines; it is a staging effect, not the presence of a reheater in the cycle. Final Answer: All of these

Question 15

Steam turbine performance — definition of stage efficiency The “stage efficiency” of a steam turbine stage is defined as the ratio of the work done on the blades per kilogram of steam to the total energy supplied per stage per kilogram of steam. Ide…

Accepted Answer

Introduction / Context: Turbine performance is expressed through several efficiencies that isolate different loss mechanisms. “Stage efficiency” aggregates the quality of both stationary and moving elements in one stage and is frequently used for preliminary design and performance guarantees. Given Data / Assumptions: Single turbine stage consisting of nozzles (fixed blades) and moving blades. Steady flow of steam with measurable inlet and exit states. Negligible shaft mechanical losses within the definition of stage efficiency. Concept / Approach: Stage efficiency η_stage compares the useful work actually obtained in the rotor (per kg of steam) to the total energy supplied to that stage (per kg). The “total energy supplied per stage” includes the isentropic heat drop available to the stage adjusted by nozzle performance, capturing how effectively the stage converts available enthalpy into rotor work. Step-by-Step Solution: Define: η_stage = (work on blades per kg) / (total energy supplied per stage per kg).Distinguish from blading (diagram) efficiency: η_diagram = (work on blades) / (kinetic energy supplied to blades).Distinguish from nozzle efficiency: η_nozzle = (actual KE at nozzle exit) / (ideal isentropic heat drop through nozzle).Mechanical efficiency covers shaft/gear losses and is separate from fluid-dynamic stage losses. Verification / Alternative check: When nozzle losses are small and velocity triangles are well-matched, stage and diagram efficiencies converge; significant nozzle losses make η_stage lower than η_diagram. Why Other Options Are Wrong: Option A divides by kinetic energy at blade inlet, not by total energy fed to the stage. Option B focuses only on fixed-blade performance. Option D concerns power transmission after fluid work is produced. Common Pitfalls: Using stage efficiency to represent the entire turbine including bearings and generator—those belong to mechanical and overall plant efficiencies. Final Answer: Stage efficiency

Question 16

Nozzle flow — definition of critical pressure For a converging or converging–diverging nozzle handling steam or gas, the discharge (mass flow rate) reaches a maximum at a particular exit/back pressure. This special back pressure is called the “criti…

Accepted Answer

Introduction / Context: Nozzle sizing in turbines and ejectors relies on the concept of choked flow. As the back pressure is reduced, mass flow initially increases but eventually becomes insensitive to further reductions because the throat reaches sonic conditions. The back pressure at which this transition occurs is associated with a critical pressure ratio. Given Data / Assumptions: Steady, adiabatic flow; negligible shaft work. Single-phase gas/steam; throat well-defined. Isentropic analysis for the ideal critical condition. Concept / Approach: For isentropic flow of a perfect gas, choking occurs when the Mach number at the throat equals 1. The mass flow rate per unit area then depends only on upstream stagnation conditions. The corresponding downstream pressure equals the critical pressure p* such that p*/p0 = function of specific heat ratio. Below this back pressure, the mass flow does not increase—discharge is maximized. Step-by-Step Solution: Reduce back pressure from near-stagnation: mass flow rises as the pressure differential grows.At the critical pressure ratio, throat Mach = 1; ṁ reaches a maximum.Further reduction of exit pressure affects only the supersonic part (if a diffuser exists) or creates expansion waves but leaves ṁ unchanged for a fixed upstream state. Verification / Alternative check: Converging nozzles choke at the throat; converging–diverging nozzles can expand to supersonic speeds past the throat but the mass flow remains set by the choked throat when upstream conditions are fixed. Why Other Options Are Wrong: “Disagree” would deny well-established choking behavior used in every gas-dynamics textbook and design code. Common Pitfalls: Confusing “critical pressure” (a specific back pressure ratio) with “critical point” of a substance in phase equilibrium thermodynamics. Final Answer: Agree

Question 17

Impulse turbine kinematics — finding the nozzle (inlet) steam velocity A single-stage impulse turbine has a rotor mean diameter of 1.2 m and runs at 3000 r.p.m. The blade speed ratio (φ = U / V1) is 0.42, where U is the blade peripheral (tip) speed …

Accepted Answer

Introduction / Context: Velocity triangles in impulse turbines relate blade speed to the absolute jet velocity issued by the nozzle. The blade speed ratio φ = U/V1 is a convenient non-dimensional parameter used for design and performance matching of a single stage. Given Data / Assumptions: Mean rotor diameter D = 1.2 m. Rotational speed N = 3000 r.p.m. Blade speed ratio φ = 0.42, with φ = U / V1. Concept / Approach: First compute the blade peripheral speed U from rotational kinematics, then invert the blade speed ratio to find V1. The relation for peripheral speed is U = π * D * N / 60. Finally, V1 = U / φ. Step-by-Step Solution: Compute U: U = π * 1.2 * 3000 / 60 = π * 1.2 * 50 = 60π ≈ 188.5 m/s.Use φ = U / V1 ⇒ V1 = U / φ.Substitute values: V1 ≈ 188.5 / 0.42 ≈ 449 m/s.Round sensibly for engineering reporting: V1 ≈ 450 m/s. Verification / Alternative check: The result is consistent with typical nozzle exit velocities for impulse stages operating near 3000 r.p.m. on a 50 Hz grid using D ≈ 1.2 m, where inlet velocities of several hundred m/s are common. Why Other Options Are Wrong: 79 m/s and 188 m/s align with blade speeds, not jet speeds. 900 m/s is unrealistically high for the given φ and would require U ≈ 378 m/s, which contradicts the calculated U. Common Pitfalls: Confusing tip speed U with inlet steam velocity; misusing φ as V1/U instead of U/V1, which would invert the result. Final Answer: 450 m/s

Question 18

Impulse vs reaction — where does steam expand? In an impulse steam turbine stage, where does the pressure (and enthalpy) drop of the steam primarily occur?

Accepted Answer

Introduction / Context: Steam turbines are classified by how the enthalpy drop is apportioned between fixed and moving elements. Recognizing where the pressure drop occurs distinguishes impulse stages from reaction stages and sets expectations for velocity triangles, blade shapes, and sealing requirements. Given Data / Assumptions: Single impulse stage comprising fixed nozzles followed by moving blades. Idealized behavior in the rotor (no pressure drop) for the impulse model. Negligible leakage and secondary flows for the conceptual explanation. Concept / Approach: In an impulse stage, all (or nearly all) of the stage pressure drop occurs in the nozzles. The nozzles convert pressure energy into high kinetic energy. The rotor blades then turn the flow, extracting work primarily by changing momentum at almost constant pressure. This contrasts with reaction stages, where pressure drops in both stator and rotor. Step-by-Step Solution: Identify the function of fixed nozzles: produce high jet velocity via pressure drop.Recognize rotor action: deflect jets to change angular momentum, doing work with minimal pressure change.Conclude: expansion (pressure and enthalpy drop) is in the nozzles; rotor ideally sees constant pressure. Verification / Alternative check: Measured static pressure across impulse rotors shows near-constant values compared with pronounced drops across stators; reaction blading shows pressure reduction in both rows. Why Other Options Are Wrong: Option B describes reaction staging. Option C is incorrect: moving blades alone do not perform the expansion in an impulse stage. Option D neglects the fundamental conversion of enthalpy to kinetic energy. Common Pitfalls: Assuming that any work extraction requires pressure drop in the rotor; in impulse stages, work results from momentum change at nearly constant pressure. Final Answer: The steam is expanded in the nozzles only, experiencing a pressure drop and heat drop; across moving blades pressure ideally remains constant

Question 19

Why compound a steam turbine? Turbine compounding (velocity, pressure, or pressure-velocity compounding) is introduced for which primary reasons in practical machines?

Accepted Answer

Introduction / Context: Early single-stage impulse turbines required extremely high rotational speeds to absorb high jet velocities efficiently. Compounding spread the total enthalpy drop over multiple stages to address mechanical limits and performance. Modern turbines employ combinations of pressure and velocity compounding to meet grid and mechanical constraints. Given Data / Assumptions: High nozzle exit velocities would imply impractically high single-stage rotor speeds. Multiple stages allow tailored velocity triangles and lower relative losses. Exit losses can be reduced by staging expansion and matching flow areas. Concept / Approach: Velocity compounding (Curtis), pressure compounding (Rateau), and pressure-velocity compounding each partition the enthalpy drop to reduce per-stage velocity and blade speed. Lowering tip speed reduces mechanical stress and facilitates direct coupling to generators. Distributing expansion also curbs residual exit kinetic energy, improving efficiency. Step-by-Step Solution: Relate jet velocity to required blade speed ratio; single stages may demand excessive rpm.Introduce multiple stages to lower each stage’s velocity and optimize incidence/deflection.Observe reduction in exit kinetic energy and better matching to practical rotor speeds.Conclude: compounding serves all listed purposes simultaneously. Verification / Alternative check: Historical Curtis wheels enabled acceptable rpm for early generators; modern multi-stage reaction/impulse machines demonstrate higher efficiencies than equivalent single-stage designs. Why Other Options Are Wrong: Selecting only one reason ignores the interrelated benefits of compounding on speed, efficiency, and exit losses. Common Pitfalls: Assuming compounding is only for speed control; it also strongly affects losses, stage loading, and manufacturability. Final Answer: All of these

Question 20

Defining “efficiency ratio” in steam turbines Evaluate the statement: “The efficiency ratio is the ratio of the total useful heat drop to the total isentropic heat drop.” Is this definition correct in turbine performance terminology?

Accepted Answer

Introduction / Context: Steam-turbine literature uses several related ratios to express how much of the ideal (isentropic) enthalpy drop is actually realized as useful work. One such term is the “efficiency ratio,” which compares realized heat drop to the ideal benchmark across the overall expansion. Given Data / Assumptions: Overall turbine expansion from inlet to exhaust. Isentropic reference between the same two states. Useful heat drop is the enthalpy fall contributing to shaft work, excluding kinetic energy carry-over and losses. Concept / Approach: If the useful (actual) heat drop equals the sum of effective stage enthalpy drops contributing to rotor work, then comparing this with the ideal isentropic drop provides a global efficiency-type index. While terminology can vary by text (overall or internal efficiency), the statement captures the intended ratio known as “efficiency ratio.” Step-by-Step Solution: Define ideal reference: total isentropic heat drop between inlet and exhaust states.Define useful heat drop: actual enthalpy decrease converted to shaft work, net of kinetic carry-over.Form the ratio: efficiency ratio = useful heat drop / isentropic heat drop.Interpretation: values less than 1 indicate losses due to friction, incidence, leakage, and residual kinetic energy. Verification / Alternative check: Manufacturer performance sheets often present “internal/overall efficiency” calculated against an isentropic baseline; the described ratio is consistent with that practice. Why Other Options Are Wrong: Choosing “Disagree” would conflict with common usage where realized heat-drop ratios against isentropic references define efficiency-type quantities. Common Pitfalls: Mixing this ratio with “reheat factor,” which compares cumulative stage drops to the isentropic drop; related but conceptually distinct measures. Final Answer: Agree

Steam Nozzles and Turbines Questions