Machine Design Board Exam Reviewer

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Which instruments is used to measure humidity of the atmosphere continuously?

a. b. c. d.

Barograph Thermograph Hydrograph Thermo-hydrograph

Entrance losses between tank and pipe or losses through elbows, fittings and valves are generally expresses as a functions of:

a. b. c. d.

Kinetic energy Pipe diameter Friction factor Volume flow rate

The air that contains no water vapor is called:

a. b. c. d.

Zero air Saturated air Dry air Humid air

In psychrometric chart, the constantenthalpy lines coincide with constanttemperature lines at temperature

a. b. c. d.

Above 50˚C Below 40 ˚C Below 50 ˚C Above 10 ˚C

The amount of moisture in air depends on its

a. b. c. d.

pressure volume temperature humidity

The deep body temperature of healthy person is maintained constant at

a. b. c. d.

27 deg C 37 deg C 47 deg C 48 deg C

By increasing the condenser pressure in vapor compression cycle, which of the following will increase? (use per unit mass analysis)

a. b. c. d.

Refrigerating effect COP Specific volume at suction Compressor work

By increasing the condenser pressure in vapor compression cycle, which of the following will decrease? (use per unit mass analysis)

a. b. c. d.

Moisture content after expansion Compressor power Heat rejected from condenser Mass flow rate

If the pressure drop in the condenser increases in a vapor compression cycle, which of the following will increase? (use per unit mass analysis)

a. b. c. d.

Mass flow rate Compressor power Heat rejected in the condenser Specific volume at suction

If the pressure drop in the condenser increases in a vapor compression cycle, which of the following will decrease? (use per unit mass analysis)

a. b. c. d.

Refrigerating effect Mass flow rate Heat rejected in the condenser Compressor work

If the pressure drop in the condenser increases in a vapor compression cycle, which of the following will not be affected? (use per unit mass analysis)

a. b. c. d.

Compressor power Mass flow rate Heat rejected in the condenser COP

If the pressure drop in the evaporator increases in a vapor compression cycle, which of the following will increase? (use per unit mass analysis)

a. b. c. d.

Refrigerating effect Vaporizing temperature Heat rejected in the condenser COP

If the pressure drop in the evaporator increases in a vapor compression cycle, which of the following will decrease? (use per unit mass analysis)

a. b. c. d.

Specific volume at suction Compressor power Heat rejected in the condenser COP

By lowering the condenser pressure in Rankine cycle, which of the following will decrease? (use per unit mass analysis)

a. b. c. d.

Pump work Turbine work Heat rejected Cycle efficiency

By increasing the Boiler pressure in Rankine cycle, which of the following will decrease? (use per unit mass analysis)

a. b. c. d.

Heat rejected Pump work Cycle efficiency Moisture content

By superheating the steam to a higher temperature in Rankine cycle, which of the following will decrease? (use per unit mass analysis)

a. b. c. d.

Moisture content at the turbine exhaust Turbine work Heat added Heat rejected

By superheating the steam to a higher temperature in Rankine cycle, which of the following will increase? (use per unit mass analysis)

a. b. c. d.

Moisture content at the turbine exhaust Pump work Condenser pressure Cycle efficiency

By superheating the steam to a higher temperature in Rankine cycle, which of the following will increase? (use per unit mass analysis)

a. b. c. d.

Moisture content at the turbine exhaust Pump work Condenser pressure Cycle efficiency

By reheating the steam before entering the second stage in Rankine cycle, which of the following will decrease?

a. b. c. d.

Turbine work Moisture content after expansion Heat added Heat rejected

When Rankine cycle is modified with regeneration, which of the following will increase?

a. b. c. d.

Turbine work Heat added Heat rejected Cycle efficiency

a. b. c. d.

Sum of the maximum demand over the simultaneous maximum demand.

a. b. c. d.

Use factor Capacity factor Demand factor Diversity factor

Regenerative with feed heating cycle with infinite number of feedwater heaters thus efficiency is equal to:

a. b. c. d.

Otto cycle Stirling cycle Erricson cycle Carnot cycle

A type of turbine used in desalination of sea water.

a. b. c. d.

Back pressure turbine Passout turbine Peaking turbine Reaction turbine

States that when conductor and a magnetic field move relatively to each other, an electric voltage is induced in the conductor.

a. b. c. d.

Maxwell’s law Kirchoff’s law Faraday’s law Newton’s law

Transfers heat directly to electrical energy by utilizing thermoionic emissions.

a. b. c. d.

Thermoionic motor Thermoionic generator Thermoionic convertor Thermoionic cell

Is the largest group of coal containing 4686% of fixed carbon and 20 to 40% volatile matter.

a. b. c. d.

anthracite Sub anthracite Bituminous Sub-bituminous

When 1 gram of coal is subjected to a temperature of about 105C for a period of 1 hour, the loss in weight of the sample gives the:

a. b. c. d.

Volatile matter and moisture ash Fixed carbon Moisture content

When 1 gram of sample coal is placed in a crucible and heated 950oC and maintained at that temperature for 7 minutes, there is a loss in weight due to elimination of:

a. b. c. d.

Volatile matter and moisture ash Fixed carbon Moisture content

Consist of hydrogen and certain hydrogen carbon compounds which can be removed from coal by heating.

a. b. c. d.

Moisture content Product of combustion ash Volatile matter

By heating 1 gram of coal in an uncovered crucible until the coal is completely burned, the _______ will formed.

a. b. c. d.

Volatile matter and moisture ash Fixed carbon Moisture content

Caking coal are used to produce coke by heating in a coke oven in the absence of ___ with volatile matter driven off.

a. b. c. c.

air Oil oxygen nitrogen

Gindability of standard coal is:

a. b. c. d.

80 90 100 110

Major constituent of all natural gases is:

a. b. c. d.

ethane methane propane cethane

Two types of fans are:

a. b. c. d.

Centrifugal and axial Tangential and rotary Reciprocating and axial Centrifugal and rotary

Enthalpy of substance at specified state due to chemical composition.

a. b. c. d.

Enthalpy of reaction Enthalpy of combustion Enthalphy of formation Enthalpy of product

A type of boiler used for super critical pressure operation:

a. b. c. d.

La Mont boiler Once-through circulation boiler Force Circulation boiler Natural circulation boiler

Economizer in a water tube boiler is heated by:

a. b. c. d.

Electric furnace Electric current Incoming flue gas Outgoing flue gas

a. b. c. d.

Radiant superheater Desuperheater Convective Superheater Pendant superheater

Regenerative superheater is a storage type of heat exchangers have an energy storage medium called:

a. b. c. d.

matrix regenerator boiler recuperator

Stirling cycle uses a _______ as working fluids.

a. b. c. d.

Incompressible gas Incompressible fluids Compressible refrigerant Compressible fluids

In stirling process, the heat is added during

a. b. c. d.

Isobaric process Isentropic process Isothermal process Heat process

Brayton cycle is also known as:

a. b. c. d.

Carnot cycle Joule cycle Diesel cycle Rankine cycle

Is applied to propulsion of vehicles because of certain practical characteristics.

a. b. c. d.

Diesel cycle Otto cycle Carnot cycle Brayton cycle

Heat exchangers typically involve:

a. b. c. d.

No work interactions No heat interactions No energy interactions None of these

A device that is used to convert the heat to work is called:

a. b. c. d.

adiabatier regenerator Heat engines None of these

The objective of a heat pump is to maintain a heated space at:

a. b. c. d.

Low temperature High temperature Medium temperature None of these

A process is called _____________ if no irreversibilities occur outside the system boundaries during the process.

a. b. c. d.

Externally reversible Internally reversible reversible None of these

An energy interaction which is not accompanied by entropy transfer is

a. b. c. d.

energy heat work None of these

The only devices where the changes in kinetic energy are significant are the

a. b. c. d.

compressor pumps Nozzles and diffusers None of these

The distance between the TDC and BDC in which the piston can travel is the

a. b. c. d.

Right extreme position Displacement stroke Stroke of the Engine Swept Stroke

In compression-engine, the combustion of air-fuel mixture is self-ignited as a result of compressing the mixture above its

a. b. c. d.

Self developed temperature Mixing temperature Self feed temperature Self ignition temperature

The superheated vapor enters the turbine and expands isentropically and produces work by the rotating shaft. The _________ may drop during the process.

a. b. c. d.

density viscosity Temperature and pressure None of these

Only _______ of the turbine work output is required to operate the pump

a. b. c. d.

.01% .02% .03% .04%

Superheating the steam to higher temperatures decreases the moisture content of the steam at the ____________.

a. b. c. d.

Turbine inlet Compressor inlet Compressor exit Turbine exit

Regeneration also provides a convenient means of dearating the feedwater to prevent

a. b. c. d.

Boiler explosion Boiler scale production Boiler corrosion Compressor damage

Can be applied in Steam turbine cycle (rankine), Gas turbine cycle (Brayton) and Combined cycle.

a. b. c. d.

Hydroelectric plant Nuclear power plant Cogeneration plant Tidal power plant

In a rankine cycle with fixed turbine inlet conditions. What is the effect of lowering the condenser pressure, the heat rejected will:

a. b. c. d.

increase decrease Remains the same None of these

How do the following quantities change when the simple ideal Rankine cycle is modified with regeneration? The heat rejected will:

a. b. c. d.

Increase decrease Remains the same None of these

It is an obvious reason for incomplete combustion.

a. b. c. d.

Insufficient carbon Insufficient air Insufficient nitrogen Insufficient oxygen

A rule of thumb is that the COP improves by ____ for each oC the evaporating temperature is raised or the condensing temperature is lowered

a. b. c. d.

2-4% 6-7% 1-5% 6-10%

Are generally more expensive to purchase and install than other heating systems, but they

a. b. c. d.

The most widely used absorption system is the ammonia-water system, where ammonia is served as refrigerant and water as the

a. b. c. d.

cooling heating Heating and cooling Transport medium

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