Will the thermal contact resistance be greater for smooth or rough plain surfaces?

Q: A heat engine with a thermal efficiency of 45 percent rejects 500 kJ/kg of heat. How much heat does…

A: Given:  Efficiency = 45 %  heat rejected, QC = 500 kJ/kg

Q: Can an object be both a good absorber and a good reflector at the same time? Why, or why not?

A: A good absorber object is an object that can absorb all the radiations without reflecting while a…

Q: A steel rod (p = 7860 kg/m³) has a length of 3.31 m. It is bolted at both ends between immobile…

A: Taking, Y = 2×1011N/m2            α=10−5/oC       Q= 3130 J          Heat capacity of steel, S =…

Q: If you touch the metal sides inside of an oven with a bare hand, you’re in trouble. But hold your…

A: Metals have more free electrons to carry energy, in order, to conduct electricity. That is why…

Q: Discuss the purpose of a layer of copper or aluminum on the bottom of stainless steel cookware?

A: Copper and aluminum are the very good and efficient conductors of heat.

Q: Two shirts are warmer than a single shirt of double thickness . Why?

A: Insulators are the material which is a bad conductor of heat. Air layers behave as a good insulator.

Q: How much heat transfer is necessary to raise the temperature of a 0.200-kg piece of ice from −20.0°C…

A: Given: mass of ice piece, m = 0.200 kg  initial temperature, Ti = −20.0 °C final temperature, Tf =…

Q: Consider two metal plates separated by air.  A temperature gradient separating the plates gives a…

A: Thermal energy transfer = kA t△θ /△x temperature gradient k△θ /△x = 24 j/ m2s A= 1X10-4 S…

Q: Steel plates are commonly attached to each other with rivets, which are slipped into holes in the…

A: The steel plates are generally attached together by the rivets. Rivets are hot, they slip into the…

Q: The rate of heat flow by conduction through a slab does NOT depend upon the *

A: Heat flow is given by ∆Q∆t=-kA∆T∆x

Q: At what common temperature would a block of wood and a block of metal feel equally cold or equally…

A: for any object feel equal cold or equal hot when it is touched since the temperature of any object…

Q: When can you add heat to object without raising its temperature?

A: When two phases co-exists in a system, any heat added or removed from the system will result in…

Q: If the amount of heat energy given to an iron rod is {53} calories, then its value in joules is.

A: The heat energy given to the iron rod is 53 cal. The energy in 1 cal is  41.184 J. The heat energy…

Q: Consider two surfaces pressed against each other. Now the air at the interface is evacuated. Will…

A: The thermal contact resistance is directly proportional to the roughness of the surface and…

Q: When determining the specific heat of a metal specimen, why must the water in the inner cup be…

A: Determining Specific Heat

Q: A submerged heater is used to keep an aquarium above room temperature. Where should the heater be…

A: Hot water has low density while cold water has high density .

Q: Can an object be good absorber and a good reflector at the same time? Why, or why not?

A: A good absorber reflects very little light. Black is good absorber and white is a good reflector.

Q: Is there any connection between object's feeling hot or cold and its thermal conductivity?

A: Thermal conductivity is the amount of heat transferred per unit time through unit area with a…

Q: Explain why a marble floor appears colder than cemented floor in winter though both are at same…

A: We feel an object cold because it takes away heat from our body when we come into contact with that…

Q: Why temperature of hand increases when we rub it against each other?

A: Reason : When you rub your hands together, the action of scraping the surface of your skin back and…

Q: The specific heat of concrete is greater than that of soil. Given thisfact, would you expect a…

A: Introduction: The amount of heat required to raise the temperature of a 1 kg body by 1° C is called…

Q: The ends of glass tube become round on heating, why?

A: The end of a glass tube become round on heating because when the glass tube is cooled, its molecules…

Q: How does heat transfer work within the bulk of an object?

A: The Process through which the heat transfer work in the bulk of the object is the same as the…

Q: the cloth around the end of his slotted spoop while stirring the boiling milk in his large badha

A: The heat is transferred from a hot body to comparatively colder body to maintain thermal…

Q: If a piece of lead is hammered, it is found to be warmer.Why?

A: Every time a piece of lead is hammered, the kinetic energy of the hammer gets transferred to the…

Q: Why does a concert violinist must usually retune his instrument when he enters a warm room?

A: Given:  violin

Q: If the amount of heat energy given to an iron rod is {39} calories, then its value in joules is.

A: Given: The heat energy given to the iron rod is 39 cal.

Q: Does a body at 0 degree C radiate any heat?

A:

Q: If two objects are in thermal equilibrium, that means they have the same

A: Thermal equilibrium is the state in which heat transfer between the two object is zero. The heat…

Q: Can two objects be in thermal equilibrium if they are not touching ?

A: Zeroth law of thermodynamics If two objects A and B are in thermal equilibrium with another object…

Q: Woolen clothes are worn in winter, Why?

A: Woollen clothes are worn in winter, because air is a poor conductor of heat.

Q: Consider an insulated pipe exposed to the atmosphere. Will the critical radius of insulation be…

A:

Q: How a thermometer works?

A:

Q: Why are mittens warmer than gloves on a cold day?

A: Gloves have larger surface area than the mittens since the gloves have individual fingers. This…

Q: Consider a window glass consisting of two 4-mmthick glass sheets pressed tightly against each other.…

A: The rate at which heat transfer occurs when there is a variation in temperature is termed as heat…

Q: The energy stored in a foot of snow on a steel roof is

A: NOTE: The question must be (on a steep roof) instead of (on a steel roof) To find out which type of…

Q: An iron nail becomes hot when it is hammered, Why?

A: Whenever there is an increase in temperature of an object, it is due to the increase in the object’s…

Q: An object radiating energy at night is in contact with the relatively warm Earth. How does its…

A:

Q: How does the thermal resistance network associated with a single-layer plane wall differ from the…

A: Five single-layered resistances connected in series are involved in the thermal resistance network…

Q: A thermal conductor is heated at one end , What is the theoretical value of its thermal conductivity…

A: Heat flow rate (Q),