A. conduction
B. convection
C. radiation
D. scattering
E. convection and radiation
Correct Answer: conduction ✔
Last Updated: January 25, 2019
Related MCQs
- According to Wien’s law, the wavelength corresponding to maximum energy is proportion to __________?
- Depending on the radiating properties, a body will be opaque when __________?
- Depending on the radiating properties, a body will be white when__________?
- The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as__________?
- The thermal diffusivities for solids are generally__________?
- According to Stefan’s law, the total radiation from a black body per second per unit area is proportional to__________?
- Depending on the radiating properties, a body will be black when__________?
- The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit__________?
- 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is__________?
- The emissive power of a body depends upon its__________?
- The ratio of the energy absorbed by the body to total energy falling on it is called__________?
- The amount of radiation mainly depends on__________?
- Absorptivity of a body will be equal to its emissivity__________?
- Depending on the radiating properties, body will be transparent when__________?
- Two plates spaced 150 mm apart are maintained at 1000°C and 70°C. The heat transfer will take place mainly by __________?
- In regenerator type heat exchanger, heat transfer takes place by__________?
- If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of__________?
- A perfect black body is one which__________?
- Planck’s law holds good for__________?
- A grey body is one whose absorptivity __________?
- The thermal diffusivities for gases are generally__________?
- Thermal diffusivity of a substance is __________?
- Stefan Boltzmann law is applicable for heat transfer by __________?
- The unit of Stefan Boltzmann constant is __________?
- Log mean temperature difference in case of counter flow compared to parallel flow will be__________?
- According to Stefan-Boltzmann law, ideal radiators emit radiant energy at a rate proportional to__________?
- In free con-vection heat transfer, Nusselt number is function of__________?
- Which of the following property of air does not increase with rise in temperature __________?
- The energy distribution of an ideal reflector at higher temperatures is largely in the range of __________?
- The value of Prandtl number for air is about __________?
- Total emissivity of polished silver compared to black body is__________?
- The value of the wavelength for maximum emissive power is given by __________?
- The unit of overall coefficient of heat transfer is__________?
- All radiations in a black body are__________?
- According to Kirchoff’s law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a __________?
- Joule sec is the unit of__________?
- The concept of overall coefficient of heat transfer is used in case of heat transfer by__________?
- In counter flow heat exchangers__________?
- Fourier’s law of heat conduction is valid for__________?
- LMTD in case of counter flow heat exchanger as compared-to parallel flow heat exchanger is __________?
- According of Kirchhoff’s law__________?
- A steam pipe is to be insulated by two insulating materials put over each other . For best results__________?
- In heat exchangers, degree of approach is defined as the difference between temperatures of__________?
- A non-dimensional number generally associated with natural convection heat transfer is__________?
- Emissivity of a white polished body in comparison to a black body is__________?
- Two balls of same material and finish have their diameters in the ratio of 2 : 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of__________?
- Heat conducted througfi unit area and unit thick face per unit time when temperature difference between opposite faces is unity,is called__________?
- A grey body is one whose absorptivity__________?
- The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as __________?
- In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by__________?
- Unit of thermal diffusivity is__________?