Description : A process in which heat energy is transferred by the flow of fluid. a. Convection b. Conduction c. Radiation d. Sublimation
Last Answer : Convection
Description : _________ is the transition of a given substance from the solid to the gas phase with no intermediate liquid stage. a. Convection b. Conduction c. Radiation d. Sublimation
Last Answer : Sublimation
Description : A process by which heat is transferred through a material without a bulk movement of the material. a. Convection b. Conduction c. Radiation d. Emission
Last Answer : Conduction
Description : How is heat transferred? A. By conduction B. By convection C. By radiation D. All of the above
Last Answer : All of the above
Description : The flow of a fluid when heat is transferred by convection. a. placidity b. mass flow c. convection current d. heat transfer
Last Answer : convection current
Description : It is the deposition of radiant energy as heat into an absorbing body. a. Radiation b. Ionization c. Convection d. Insolation
Last Answer : Insolation
Description : What refers to the transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles? A. Conduction B. Convection C. Radiation D. Electrification
Description : reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by ... Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these
Last Answer : Option C
Description : A convection process in which an external device, such as a fan, is used to produce the fluid flow. a. Forced Convection b. External Convection c. Placid Convection d. Thermionic Convection
Last Answer : Forced Convection
Description : Mode of heat transfer in which the fluid moves under the influence of changes in fluid pressure produced by external work is called (A) Radiation (B) Natural convection (C) Forced convection (D) Conduction
Last Answer : (C) Forced convection
Description : Fluid motion in the natural convection heat transfer between a solid surface and a fluid in contact with it, results from the (A) Existence of thermal boundary layer (B) Temperature gradient produced ... difference (C) Buoyancy of the bubbles produced at active nucleation site (D) None of these
Last Answer : (D) None of these
Description : Which of the following represents the perpetual motion of the first kind (a) engine with 100% thermal efficiency (b) a fully reversible engine (c) transfer of heat energy from low ... its own energy (e) production of energy by temperature differential in sea water at different levels.
Last Answer : Answer : d
Description : In convection heat transfer, if heat flux intensity is doubled then temperature difference between solid surface and fluid will ?
Last Answer : Get doubled.
Description : What refers to the rate of thermal radiation emitter per unit area of a body? A. Thermal conductivity B. Absorptivity C. Emissivity D. Emissive power
Last Answer : Emissive power
Description : The energy of molecular motion appears as (a) heat (b) potential energy (c) surface tension (d) friction (e) increase in pressure.
Last Answer : Answer : a
Description : Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of- (1) Convection only (2) Conduction and convection only (3) Radiation and convection only (4) Convection, conduction and radiation
Last Answer : (3) Radiation and convection only Explanation: Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
Description : ____ is the transfer of energy in the form of electromagnetic waves. a. Compulsion c. Convection b. Radiation d. Conduction
Last Answer : b. Radiation
Description : Without electrical, mechanical, gravitational, surface tension and motion effects, a system is called _____ system. A. Simple B. Simple compressible C. Compressible D. Independent
Last Answer : Simple compressible
Description : What refers to the heating of the earth’s atmosphere not caused by direct sunlight but by infrared light radiated by the surface and absorbed mainly by atmospheric carbon dioxide? A. Greenhouse effect B. Global warming C. Thermal rise effect D. Ozone effect
Last Answer : Greenhouse effect
Description : Pick out the wrong statement. (A) Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection (B) The ratio NNu /NRe . Npr is ... convection to that by conduction (D) The Colburn jH factor for heat transfer is given by Nst Npr
Last Answer : (D) The Colburn jH factor for heat transfer is given by Nst Npr
Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in – (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection
Last Answer : (2) Convection Explanation: The process of heat transfer from one place to an-other place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the ... heated particles of the substance. The fluids (liquids and gases) are heated by this process.
Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in - (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection
Last Answer : (2) Convection Explanation: The process of heat transfer from one place to another place without the movement of particles is called conduction,
Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection
Description : Utilizing the answer to the previous problem, estimate the overall or average increase in temperature ( ΔT) of the concrete roof from the energy absorbed from the sun during a12hour day. Assume that all of the radiation absorbed goes into ... °C b. 8.9°C c. 9.9°C d. 10.9°C formula: ΔQ = m c ΔT
Last Answer : 7.9 °C
Description : In the process of radiation, energy is carried by electromagnetic waves. What is the speed of electromagnetic waves? A. 182,000 miles/second B. 184,000 miles/second C. 186,000 miles/second D. 188,000 miles/second
Last Answer : 186,000 miles/second
Description : Fourier's law applies to the heat transfer by (A) Convection (B) Radiation (C) Conduction (D) All (A), (B) & (C)
Last Answer : (C) Conduction
Description : In which mode of heat transfer, the Biot number is important? (A) Transient heat conduction (B) Natural convection (C) Forced convection (D) Radiation
Last Answer : (A) Transient heat conduction
Description : When warm and cold liquids are mixed, the heat transfer is mainly by (A) Conduction (B) Convection (C) Radiation (D) Both (A) & (C
Last Answer : (B) Convection
Description : If heat transfer rate varies with the time, it is termed as (A) Forced convection (B) Steady state conduction (C) Monochromatic radiation (D) None of these
Description : View factor is important in heat transfer by (A) Steady state conduction (B) Natural convection (C) Forced convection (D) Radiation
Last Answer : (D) Radiation
Description : Heat transfer by __________ may not necessarily require the presence of a medium. (A) Conduction (B) Natural convection (C) Forced convection (D) Radiation
Description : In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by (A) Conduction (B) Convection (C) Radiation (D) Cannot be predicted
Last Answer : (C) Radiation
Description : Maximum heat transfer in high temperature furnaces is by (A) Conduction (B) Convection (C) Radiation (D) Either (A), (B) or (C); depends on the type of furnace
Description : Gibbs phase rule finds application, when heat transfer occurs by (A) Conduction (B) Convection (C) Radiation (D) Condensation
Last Answer : (D) Condensation
Description : In a furnace with heating element temperature at 1700°C, the dominant mechanism of heat transfer will be (A) Conduction (B) Radiation (C) Natural convection (D) Forced convection
Last Answer : (B) Radiation
Description : Heat transfer by __________ is almost absent in case of fluidised bed drying operation. (A) Radiation (B) Conduction (C) Convection (D) Both (B) & (C)
Last Answer : A) Radiation
Description : Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by (A) Conduction (B) Convection (C) Radiation (D) Both 'a' & 'b'
Description : ____ is the transfer of heat from one particle to another by contact. a. Conduction c. Radiation b. Convection d. Combustion
Last Answer : a. Conduction
Description : What refers to the amount of heat removed from the cooled space in BTS’s for 1 watt-hour of electricity consumed? A. Cost efficiency rating B. Energy efficiency rating C. Coefficient of performance D. Cost of performance
Last Answer : Energy efficiency rating
Description : What refers to the amount of energy absorbed or released during a phase-change process? A. Molar heat B. Latent heat C. Vaporization heat D. Condensation heat
Last Answer : Latent heat
Description : What refers to the portion of the internal energy of a system associated with the kinetic energies of the molecules? A. Translational energy B. Spin energy C. Rotational kinetic energy D. Sensible energy
Last Answer : Sensible energy
Description : What form of energy refers to those a system possesses as a whole with respect to some outside reference frame, such as potential and kinetic energies? A. Macroscopic form of energy B. Microscopic form of energy C. Internal energy D. External energy
Last Answer : Macroscopic form of energy
Description : Work done in pushing a fluid across a boundary, Usually into or out of a system a. Flow Work b. Flow Energy c. Both a & b d. None of the above
Last Answer : Both a & b
Description : The flow energy of 5 ft3 of a fluid passing a boundary to a system is 80,000 ft-lb. Determine the pressure at this point. a. 222 psi b. 333 psi c. 444 psi d. 111 psi formula: Ef= pV
Last Answer : 111 psi
Description : The flow energy of 150 L of a fluid passing a boundary to a system is 110 kJ. Determine the pressure at this point a. 733.33 kPa b. 833.33 kPa c. 933.33 kPa d. 633.33 kPa
Last Answer : 733.33 kPa
Description : What refers to the transfer of energy due to the emission of electromagnetic waves or photons? A. Conduction B. Convection C. Radiation D. Electrification
Last Answer : Radiation
Description : The energy associated with individual molecules in a gas, liquid or solid. a. Specific Energy b. Molecular Energy c. Internal Energy d. Phase Energy
Last Answer : Internal Energy
Description : Which of the following occurs in a reversible polytrophic process? a. Enthalpy remains constant b. Internal energy does not change c. Some heat transfer occurs d. Entropy remains constant
Last Answer : Some heat transfer occurs
Description : Which of the following best describes heat? a. The capacity to do work b. Forces times distances c. Sum of thermal and chemical energy d. An energy transfer due to temperature difference
Last Answer : An energy transfer due to temperature difference
Description : The first law of thermodynamics may be expressed in the following equivalent a. the net heat transfer id equal to the network b. the sum of the total energy forms leaving the system boundary is ... neither be created nor destroyed but only converted from one form to another d. all of the above
Last Answer : all of the above