When would I have the highest potential energy? What is it called when the molecules in an object stop moving? When would I have the highest kinetic energy? Which has more potential energy: A A lb man standing on a 60 ft. Which has more energy? A A cup of sand at room temperature B A cup of sand that has been in the freezer for 3 days. Cold always moves to hot. A False B True. Which of the following is an example of radiation? It is a pleasant fall day and the temperature outside is 55 degrees Fahrenheit.
You decide to take a hot shower after a tough football practice. To keep the bathroom from fogging up, you open the window. In what way is the heat from the shower being tranferred to the outside? Billy is in a competition to see who can carry an ice cube the furthest before it melts. He decides to where gloves. Why does he do this? Sally goes to her track meet on Saturday.
Conduction, convection and radiation test questions
It is very hot and she is out in the sun all day. By the time she gets to her last race, her skin is hot to the touch and she feels a little ill.
What is the main form of energy transfer that made Sally's skin so hot? It is not possible to create or destroy energy. Which of following is a conductor?
This picture most likely shows molecules in a: A liquid B gas C solid. Describe how molecules move differently in a solid, liquid, and a gas? Tell how this changes when energy is added. What is the difference between conduction and convection? Billy does an experiment to see what type of food has the fewest calories. Based on his results, which food most likely has the least amount of calories? There is an error in this experiment. What might be the cause of this error?
Note: Answer this question as Part 1 answer and then Part 2 answer. Use the table for the analysis. Which food ingredient of the ones we covered in class typically has the fewest calories? Which of the following is a conductor? If you did not cover the lid to your solar oven, heat would escape. This is an example of heat loss through A convection B radiation C conduction.
Which of these is the best example of potential energy? D A feather floating in the air down a hill.Follow-up on this answer. Related Questions. Still Curious? Absolute zero is a minimum temperature. Is there a maximum temperature? Explain 2. What is the temperature of a vacuum? Explain 3. A metal ball can pass through a metal ring. When the ball is heated, however,it gets stuck in the ring.
What would happen if the ring, rather than the ball, were heated? Explain why lakes freezes first at the surface. At absolute zero, things have fallen into the lowest energy state that they have. Infinite temperature would mean having an equal chance to be in any of the possible states. However, the states just keep going on up to higher and higher energy.Nikon p1100
For example, you can have states with any number of photons. As the chance of being in any state gets close to equal, the average energy blows up toward infinity. So with some finite amount of energy around, the temperature stays finite.
With more energy, it could always get larger, so there's no upper limit. A vacuum can have any temperature. The temperature determines how much random thermal radiation, mostly electromagnetic waves, is present. The vacuum of distant space happens to have a temperature just under 3K, very cold but not as cold as one can reach in an ordinary lab.
At temperatures over about a billion K not only electromagnetic waves but even electrons and positrons start to show up. I guess at that point, you might want to stop calling a vacuum by that name. Assuming the ring were made of similar material, it would also expand, making it easier for the ball to pass through.
Usually the heat is flowing out to the cold air from the surface. The bottom is usually warmer than the air, if it's been sitting under liquid water. That means that the coldest water can just float on top, where it can cool down even more.
Mike W. Can one object be hotter than another if they are at the same temperature? No, what we mean by 'hotter' in this context is 'having higher temperature', so by definition that's impossible. One object might feel hotter, but that's only because it might conduct heat better than the other.
This reminds me of another important principle. If two objects can freely exchange energy they will come to the same temperature.Many people think that heat and temperature are related to each other, but they are different concepts as discussed in class.
How much of the processes or differences did you understand this week? Below is a quiz on heat and temperature, at Grade 7 level based on Alberta, Canada schools. All substances are made of tiny particles to small to be seen.
They are always moving and have spaces in them. Forgot your password? Speak now. Science-heat And Temperature Quiz Grade 7.
300+ TOP HEAT TRANSFER Multiple Choice Questions and Answers
Please take the quiz to rate it. All questions 5 questions 6 questions 7 questions 8 questions. Feedback During the Quiz End of Quiz. Play as Quiz Flashcard. Title of New Duplicated Quiz:. Duplicate Quiz Cancel. More Temperature Quizzes. Matter In Our Surroundings. Featured Quizzes.S7 active xda
Related Topics. Questions and Answers. Remove Excerpt. Removing question excerpt is a premium feature. The particle model of matter, clearly states:. Atoms are actually found only in solids and liquids. Something else is in Gas. Gas turning into a solid is called:. Back to top. Sign In with your ProProfs account. Not registered yet? Sign Up. I agree to the Terms of Services and Privacy Notice.
Already have an account?HVACR practice exams can be used for self-assessment, professional-growth, and certification exam preparation. A question EPA practice test comes with our materials.
The questions are based on industry standards and offer a comprehensive coverage of the fundamental subject matter found on most HVACR certification exams. Our question HVAC practice test provides:. Grade Answers as You Go. The symbol or letter for impedance is Z and it is represented by writing its magnitude and phase.
Incorrect answer. Please choose another answer. Any time there is a change of temperature indicated by the thermometer the heat level or intensity can easily be measured. In the writings of the early scientists who provided the foundations of thermodynamics, sensible heat had a clear meaning in calorimetric.
Heat, which causes a change of state without a change in temperature, is known as latent heat. An example of latent heat is water changing to ice or vice a versa. Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A sling psychrometer is a device that consist of two thermometers fitted in a hinged bracket used for spinning the two thermometers.
One of the bulbs is kept moist with distilled water on a sock or wick placed over the thermometer's tip. As the thermometers are rotated, evaporation of water from the wick lowers the temperature indicating a lower temperature than that of the dry-bulb thermometer. This is the Wet bulb temperature which will be lower than the dry bulb and can never be above dry bulb measurement.
The lower the relative humidity, the lower the wet bulb temperature. The difference in the two bulbs readings can be applied to a psychrometric chart to calculate relative humidity and other properties of air.
Compression ratio is found by dividing the absolute discharge pressure by the absolute suction pressure. PSIG is converted to absolute by adding In this problem, discharge pressure Direct type evaporators are designed to operate most efficiently with approximately 10 degrees superheat.
In order to have superheat, all liquid must be boiled away before reaching the end of the evaporator. A valve that is in the maximum open position will have liquid refrigerant flowing at a rate faster than the evaporator could boil it away; thus creating a flooded coil and liquid refrigerant going back to the compressor.
The reversing valve is the component that will reverse the flow of refrigerant when changing from air conditioning to heating. To control energy, the heat pump will incorporate outdoor thermostats to limit the auxiliary heat before the balance point is reached. When installing the outdoor unit the return air is not a factor in the installation; all of the other answers are factors involving installation.
Most manufacturers recommend 30 inches of clearance from the structure, bushes, hedges and any other obstructions. One BTU is the quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit.
Natural gas distributed for consumer use is Heat elements are made of Ni-chrome which is nickel and chromium. They are combined to create a resistance wire. A resistive load is an electrical load in which voltage and current are in phase and are converted to energy in the form of heat.ANSWER: is always constant Explanation: The system in which both the mass as well as energy cannot be transferred between system and its surrounding is called as isolated system.
As the energy can neither be transmitted nor be absorbed, the total energy of an isolated system is always constant. Temperature is the term through which we can differentiate between hot and cold. When two bodies are brought in physical contact with each other and one body has more temperature than other then hear transfer takes place from hot body to cold one.
After some time they attain a common temperature and then they are in a thermal equilibrium. These phenomena are very important in thermodynamics. In thermodynamics, work transfer occurs between system and surrounding. Work is said to be done by a system when the energy is transferred from the system and it is responsible for or counted as some external mechanical change.
When work is done by a system then it is taken as positive, and when work is done on the system by the surrounding then it is taken as negative. The symbol W is used for work transfer.
ANSWER: the internal energy of the system increases Explanation: When a system undergoes cycle, then the algebraic sum of all energy transfer across the boundaries is zero. But when a system undergoes a change of state in which both heat transfer and work transfer are involved, the net energy transfer is stored and collected within the system. If Q is the amount of heat transferred to the system and W is the amount of work transferred from the system during the process, then the net energy Q — W is stored in the system.
This energy is neither heat nor work but it is called as internal energy. For example, according to Joule, based on his experiments, energy supplied to a system in a form of heat, can be completely converted into work. But this process is not possible, because we know that in thermodynamic process internal energy of a system also increases. Thus, Heat transfer — Internal energy increase — Work transfer The complete conversion of heat into work is not possible.
Therefore heat and work are not completely interchangeable forms of energy. ANSWER: a statement that energy balance occurs when a system undergoes the change of state or the process Explanation: The first law of thermodynamics states that the energy balance occurs when a system undergoes the change of state or the process.
It states that if energy is supplied to a system in a form of heat, which can be completely converted into work energy. But practically it is not possible, because internal energy of the system also increases in the process. Thus, first law of thermodynamics does not provide information on whether the change of state or the process is feasible or not. Consider the following heat engine, The heat Q1 is transferred to the system and work W1 is done by the system.
Then system is taken to its initial position by applying work W2 on the piston and heat Q2 is rejected from the system. This is the heat engine cycle. In heat engine cycle, a net heat is transferred to the system and a net work is transferred from the system.
ANSWER: refrigerator Explanation: In heat engine cycle, a net heat is transferred to the system and a net work is transferred from the system. In the system of mass of gas confined in a cylinder and piston machine, the heat is added to the system and work is done by the system on the piston and vice versa. In stem power plant initially the heat is added from the furnace to boiler, this stem passes through the turbine and work is done, then the stem is condensed to water in condenser and the heat is rejected from the system, and finally work is done on the system to pump the water back to the boiler.
But refrigerator does not consist heat engine cycle, because in refrigerator, the work is done on the system and heat transfer takes place from the system.Unit of thermal conductivity in M. Ans: b.5 village seed
Unit of thermal conductivity in S. Ans: e. Thermal conductivity of solid metals with rise in temperature normally a increases b decreases c remains constant d may increase or decrease depending on temperature e unpredictable.
Thermal conductivity of non-metallic amorphous solids with decrease in temperature a increases b decreases c remains constant d may increase or decrease depending on temperature e unpredictable. Ans: c. When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by a conduction b convection c radiation d conduction and convection e convection and radiation.
Ans: a. When heat is transferred form hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by a conduction b convection c radiation d conduction and convection e convection and radiation.Heat and Temperature Test Questions - MCQsLearn Free Videos
Sensible heat is the heat required to a change vapour into liquid b change liquid into vapour c increase the temperature of a liquid of vapour d convert water into steam and superheat it e convert saturated steam into dry steam.
When heat is Transferred by molecular collision, it is referred to as heat transfer by a conduction b convection c radiation d scattering e convection and radiation. Heat transfer in liquid and gases takes place by a conduction b convection c radiation d conduction and convection e convection and radiation.
Which of the following is the case of heat transfer by radiation a blast furnace b heating of building c cooling of parts in furnace d heat received by a person from fireplace e all of the above. Ans: d. Heat is closely related with a liquids b energy c temperature d entropy e enthalpy.
Pick up the wrong case. Heat flowing from one side to other depends directly on a face area b time c thickness d temperature difference e thermal conductivity.
Metals are good conductors of heat because a their atoms collide frequently b their atoms-are relatively far apart c they contain free electrons d they have high density e all of the above.
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Which of the following is a case of steady state heat transfer a I. Total heat is the heat required to a change vapour into liquid b change liquid into vapour c increase the temperature of a liquid or vapour d convert water into steam and superheat it e convert saturated steam into dry steam. Cork is a good insulator because it has a free electrons b atoms colliding frequency c low density d porous body e all of the above.
Thermal conductivity of water in general with rise in temperature a increases b decreases c remains constant d may increase or decrease depending on temperature e none of the above. Thermal conductivity of air with rise in temperature a increases b decreases c remains constant d may increase or decrease depending on temperature e none of the above. Heat flows from one body to other when they have a different heat contents b different specific heat c different atomic structure d different temperatures e none of the above.
The amount of heat flow through a body by conduction is a directly proportional to the surface area of the body b directly proportional to the temperature difference on the two faces of the body c dependent upon the material of the body d inversely proportional to the thickness of the body e all of the above.
Which of the following has least value of conductivity a glass b water c plastic d rubber e air. Which of the following is expected to have highest thermal conductivity a steam b solid ice c melting ice d water e boiling water.
Thermal conductivity of glass-wool varies from sample to sample because of variation in a composition b density c porosity d structure e all of the above. Which of the following has maximum value of thermal conductivity a aluminium b steel c brass d copper e lead. Moisture would find its way into insulation by vapour pressure unless it is prevented by a high thickness of insulation b high vapour pressure c less thermal conductivity insulator d a vapour seal e all of the above.
Heat is transferred by all three modes of transfer, viz, conduction, convection and radiation in a electric heater b steam condenser c melting of ice d refrigerator condenser coils e boiler.Raja rani trailer dailymotion
According to Prevost theory of heat exchange a it is impossible to transfer heat from low temperature source to t high temperature source b heat transfer by radiation requires no medium c all bodies above absolute zero emit radiation d heat transfer in most of the cases takes place by combination of conduction, convection and radiation e rate of heat transfer depends on thermal conductivity and temperature difference.
Heat transfer by radiation mainly depends upon a its temperature b nature of the body c kind and extent of its surface d all of the above e none of the above. Thermal diffusivity is a a dimensionless parameter b function of temperature c used as mathematical model d a physical property of the material e useful in case of heat transfer by radiation.
Thermal diffusivity of a substance is. Thermal conductivity of wood depends on a moisture b density c temperature d all of the above e none of the above. 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.When would I have the highest potential energy?
What is it called when the molecules in an object stop moving? When would I have the highest kinetic energy? Which has more potential energy: A A pound man standing on a 25 ft. Which has more energy?
A A cup of sand at room temperature B A cup of sand that has been in the freezer for 3 days. Cold always moves to hot. A False B True. Which of the following is an example of radiation?
It is a pleasant fall day and the temperature outside is 55 degrees Fahrenheit. You decide to take a hot shower after a tough football practice. To keep the bathroom from fogging up, you open the window. In what way is the heat from the shower being tranferred to the outside? Billy is in a competition to see who can carry an ice cube the furthest before it melts. He decides to where gloves.
Why does he do this? Sally goes to her track meet on Saturday. It is very hot and she is out in the sun all day. By the time she gets to her last race, her skin is hot to the touch and she feels a little ill. What is the main form of energy transfer that made Sally's skin so hot? It is not possible to create or destroy energy. A True B False.
Which of following is a conductor? This picture most likely shows molecules in a: A gas B liquid C solid. Describe how molecules move differently in a solid, liquid, and a gas?
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