Chapter 2 · MCQ Read Mode

Engineering Thermodynamics

A system that allows both mass and energy to cross its boundary is:

Which of the following is an intensive property?

Heat and work are:

The zeroth law of thermodynamics forms the basis of:

The temperature at which Celsius and Fahrenheit scales read the same value is:

The value of the universal gas constant is:

For air, cp = 1.005 kJ/kg·K and cv = 0.718 kJ/kg·K. The gas constant R is:

A real gas behaves most like an ideal gas at:

Dryness fraction of dry saturated steam is:

Wet steam at a pressure where hf = 500 kJ/kg and hfg = 2200 kJ/kg has x = 0.9. Its enthalpy is:

At the critical point of water, the latent heat of vaporisation is:

The Mollier chart is a plot of:

Specific energy consumption of a plant is normally expressed as:

One kilowatt-hour of energy is equal to:

For a closed system, the first law of thermodynamics is expressed as:

For an ideal gas, internal energy is a function of:

In a constant-volume process, the work done is:

In an isothermal process of an ideal gas, the change in internal energy is:

The polytropic index n for a reversible adiabatic process is:

0.5 m³ of air at 1 bar is compressed isothermally to 0.1 m³. The work done (magnitude) is approximately:

During a throttling process, which property remains constant?

Steam enters a nozzle with negligible velocity and an enthalpy drop of 100 kJ/kg. The exit velocity is about:

In an adiabatic steam turbine with negligible KE and PE changes, work output per kg equals:

A perpetual motion machine of the first kind violates:

Air is freely expanded into an insulated vacuum. For the air:

When an evacuated, insulated rigid tank is filled with an ideal gas from a supply line at Tline, the final gas temperature is:

The indirect (heat-loss) method of finding boiler efficiency is preferred because it:

An economiser in a boiler plant recovers waste heat to:

The Kelvin-Planck statement implies that:

A perpetual motion machine of the second kind violates:

A Carnot engine works between 527 °C and 27 °C. Its efficiency is:

The Carnot cycle consists of:

The efficiency of a Carnot engine depends on:

A refrigerator operates between −3 °C and 27 °C. Its maximum (Carnot) COP is:

For the same temperature limits, COP of a heat pump is related to COP of a refrigerator by:

Which of the following is NOT a cause of irreversibility?

For an irreversible cycle, the Clausius inequality gives ∮δQ/T:

The entropy of an isolated system undergoing a real process:

An isentropic process is:

Isentropic efficiency of a compressor is defined as:

One tonne of refrigeration is equal to:

Cogeneration (combined heat and power) raises overall energy utilisation because it:

The Otto cycle consists of two isentropic processes and two:

The air-standard efficiency of an Otto cycle with r = 8 and γ = 1.4 is approximately:

For the same compression ratio and heat input, the most efficient cycle is:

For the same maximum pressure and temperature, the most efficient cycle is:

The efficiency of a Diesel cycle, for a fixed compression ratio, increases when:

The Brayton cycle is the ideal cycle for:

The efficiency of an ideal Brayton cycle depends on:

In a Rankine cycle, the process in the condenser is:

Reheating in a Rankine cycle is mainly used to:

In a vapour compression refrigeration cycle, the expansion process is:

One ton of refrigeration is equal to about:

In a lithium bromide–water absorption system, the refrigerant is:

A back-pressure steam turbine is used in industry mainly to:

A vapour-absorption refrigeration system is attractive in a plant that has:

In a four-stroke engine, the number of power strokes per revolution of the crankshaft is:

The camshaft of a four-stroke engine rotates at:

In a CI engine, fuel is ignited by:

The typical compression ratio of a diesel engine is:

Load in an SI engine is controlled by varying the quantity of mixture using the throttle. This is called:

The anti-knock quality of petrol is expressed by:

To reduce knocking in a CI engine, one should:

Engine swept volume 500 cc and clearance volume 50 cc. The compression ratio is:

An engine has IP = 50 kW and BP = 40 kW. Its mechanical efficiency is:

In a two-stroke petrol engine, the ports are opened and closed by:

The component that converts reciprocating motion of the piston to rotary motion is the:

The function of a flywheel in an IC engine is to:

A diesel generating set gives its best specific fuel consumption when loaded to about:

In selecting the rating of a DG set for a factory, the most important additional consideration beyond the running load is:

Summer air-conditioning generally involves:

In a fire-tube boiler:

Which of the following is a water-tube boiler?

The Benson boiler is characterised by:

An economiser in a boiler is used to:

Which of the following is a boiler mounting (not an accessory)?

For minimum work in a two-stage air compressor with perfect intercooling, compressing from 1 bar to 16 bar, the intermediate pressure is:

The work required for compressing air is minimum when compression is:

Refrigerant R-717 is:

R-134a replaced R-12 mainly because R-134a has:

For saturated air:

During evaporative cooling (desert cooler), which remains approximately constant?

Specific humidity of moist air is given by:

In a compressed-air system, reducing the compressor discharge pressure by 1 bar typically saves about:

Humidity control is essential in a textile spinning mill mainly because: