Junior high school physics: How to judge the low temperature, middle temperature, and high temperatu

Judged by p=u2 r.

When the resistance value r is very small, that is, the total resistance value in the circuit is very small (it may be in the case of parallel connection), p is very large, and it is a high temperature gear.

When the resistance value r is very large, that is, when the total resistance value in the circuit is large (it may be in the case of series connection), p is very small and it is a low temperature gear.

The Chinese file is between the high temperature gear and the low temperature gear, and the general household appliances will give specific values.

Extended Materials. The low temperature gear is mostly a series circuit.

The switch controls the entire circuit at any location, i.e. its role is independent of its location. There is only one path for the current, and the current that passes through one lamp must pass through the other. If one light goes out, the other must go out.

Advantages: In one circuit, if you want to control all the circuits, you can use a series of circuits; Disadvantages: As long as there is a disconnection somewhere, the entire circuit becomes an open circuit, that is, the electronic components that are connected in series.

Doesn't work.

The high temperature gear is mostly a parallel circuit.

The current from the trunk circuit is divided into two parts and flows through the individual elements in the two branches.

In parallel circuits, the switch on the trunk road is closed, and the switch on each branch road is closed, so that the bulb will shine, and the switch on the trunk road is disconnected, and the switch on each branch road is closed, and the bulb will not emit light.

The string is high and low, the two resistors in series are connected together for the high temperature gear, the parallel connection together is the low temperature gear, and only one resistor in series is the medium temperature gear.

The utilization of the power supply voltage is unchanged

p=u^2/r

The smaller the r, the larger the p, which is the heated state.

The larger the r, the smaller the p, and it is in a state of insulation.

The high temperature gear and the low temperature gear mainly refer to the high and low energy emitted, and the general household circuit voltage remains unchanged, so according to p u2 r, when the resistance r in the circuit becomes smaller, that is, p is large, it is the high temperature gear at this time; When the resistance r in the circuit becomes larger, p becomes smaller, which is the low temperature gear.

According to Joule's law.

The heat is proportional to the square of the current, proportional to the resistance, and proportional to the time of energizing. It is also reflected in the formula that the effect of electric current on heat is a squared effect. That is, the effect of a change in current on the heat produced is greater than that of resistance.

The effect of change on heat is greater.

Therefore, if the current in both states is the same, (note that the current is not the voltage), the resistance is large.

more, as a high temperature gear.

Usually the test questions are different currents and the same voltage. Then it is considered that the current with large resistance is small, and the heat is less, which is regarded as a low temperature gear.

In the circuit, it will generally have a switch on the branch, and there will also be a switch on the dry road, when the switch on the branch is closed, you can know that the two resistors are in parallel. At this time, the resistance is small and the electrical power is large. At this time, it is a high temperature gear, after the switch of its branch is disconnected, the two resistors are connected in series, then at this time, the resistance is large and the electrical power is small.

It can be clearly judged that this is a low temperature gear.

The high temperature level is the one with the highest measurement resistance or voltage. Give it satisfaction!

1.Temperature judgment: In general, high temperature refers to a higher temperature, and low temperature refers to a lower temperature.

The specific criteria for judging can be determined according to the different fields of application and the properties of the substance. For example, in the atmosphere, high temperature can refer to a temperature that exceeds normal temperature (usually 20-25 degrees Celsius), while low temperature can refer to a temperature below normal temperature. In the laboratory, the criteria for judging high and low temperatures may be different.

2.Phase change judgment: A substance undergoes a phase change at different temperatures, such as a solid becoming a liquid or a gas.

Generally speaking, the phase change is more likely to occur in the high temperature state, while the substance is more likely to remain solid in the low temperature state. Therefore, if the substance is in a liquid or gaseous state, it can be judged as a high-temperature state; If the substance is in a solid state, it can be judged to be in a low temperature state.

3.Judgment of physical properties: Different substances may exhibit different physical properties at high and low temperatures.

For example, certain substances can melt or thermally expand at high temperatures, while at low temperatures they become fragile or shrink. By observing the changes in the physical properties of a substance, it is possible to determine the temperature range in which it is located.

It is important to note that the specific criteria for judging high and low temperatures may vary depending on the field and application. In specific situations, the relevant temperature standards, material properties and experimental data can be referred to to make judgments. <>

Summary. You can follow the steps below to judge the heating and holding gear:1

Check the instruction manual or product label to confirm the function and usage of the heating and holding settings. 2.Turn on the switch on the appliance or appliance, select the heat setting, and wait a few minutes to observe the temperature change of the food or drink.

3.If the food or drink gets hot, it means that the heating gear is working properly; If there is no change, there may be a faulty appliance or appliance. 4.

Turn the appliance or appliance to heat and wait for a while to observe the temperature change of the food or drink. 5.If the food or drink is kept at a certain temperature, it means that the keep warm gear is working normally; If the temperature drops or changes erratically, there may be a faulty appliance or appliance that needs to be replaced.

You can follow the steps below to judge the heating and holding gear:1Check the label of the basic or jujube product in the manual to confirm the function and use of the heating and holding gear.

2.Turn on the switch on the appliance or appliance, select the heat setting, and wait a few minutes to observe the temperature change of the food or drink. 3.

If the food or drink gets hot, it means that the heating gear is working properly; If there is no change, there may be a faulty appliance or appliance. 4.Turn the appliance or appliance to heat and wait for a while to observe the temperature change of the food or drink.

5.If the food or drink is kept at a certain temperature, it means that the keep warm gear is working normally; If the temperature drops or changes unsteadily, it may be that the appliance or appliance is faulty or needs to be dismantled and replaced.

Generally speaking, the heating setting can heat the food or beverage to the state of hot beverage or hot food, while the heat storage setting can keep the temperature of the food or beverage unchanged or keep warm.

Dear, do you have any questions?

Can you help me see if these three questions are written correctly?

12 questions are correct, and you didn't shoot the other two questions clearly.

Good drops. Uh-huh.

For judging the high-temperature, low-temperature and medium-temperature gears, we need to first understand the principle of the temperature setting of electrical appliances. In some household appliances, such as electric fans, electric heaters, etc., there will be temperature gear settings. By adjusting the temperature level, the operating state of the electrical appliance is controlled to reach the required temperature value.

Generally speaking, the temperature range settings of electrical appliances are generally divided into high, medium and low levels, and the specific temperature range will vary depending on the appliance itself.

To judge the high temperature, low temperature and medium temperature range, we can judge by the following aspects:

1.Look at the temperature gear identification: Generally, electrical appliances will mark their temperature gear on the outside, and we can judge whether the gear is high, medium and low by looking at the logo.

2.Feel the surface of the appliance: After turning on the appliance, we can touch the surface of the appliance to feel its temperature.

If it's hot to the touch, then it's likely to be a high temperature range; If the temperature is moderate, then the gear is likely to be a medium temperature range; If it's cool to the touch, then it's likely to be a low gear.

3.Use an infrared thermometer: An infrared thermometer can directly measure the temperature of the appliance to obtain the temperature value of the surface of the appliance. By comparing the values, we can accurately determine the level of the temperature range.

In general, we can help us judge the level of electrical temperature level through the three methods of identification, feel and infrared thermometer. Through the accurate judgment of the temperature level, we can better control the operation status of the electrical appliances to achieve the temperature effect we need. <>

The utilization of the power supply voltage is unchanged

p=u^2/r

The smaller the r, the larger the p, which is the heated state.

The larger the r, the smaller the p, and it is in a state of insulation.

Well, junior high school physics, low temperature gear, medium temperature and high temperature gear are judged by some of their physical properties, this is that there is also a thermometer that can be directly broken.