What is the common temperature measurement tool in the laboratory? What is its working principle?

What is the common temperature measurement tool in the laboratory? What is its working principle?

Mercury thermometer, alcohol thermometer,
The working principle is that the liquid expands with heat and contracts with cold

What is temperature? What is the working principle of liquid thermometer? What is the principle of laboratory thermometer

1 is the physical quantity that represents the degree of cold and hot of an object, and microcosmically, it is the intensity of the thermal motion of molecules
The working principle of liquid thermometer is based on the principle of heat expansion and cold contraction
3. Thermometers in the laboratory have thermocouple thermometers. The principle is that when two different conductors contact to form a loop, the loop will generate electric potential. The magnitude of the electric potential is directly related to the temperature difference between the two contacts. This phenomenon is called thermoelectric effect. The temperature sensing element made of thermoelectric effect is thermocouple, Thermocouple thermometer is composed of thermocouple as temperature sensing element
In classical electron theory, thermoelectric potential consists of thermoelectric potential and contact potential
The thermoelectric potential is caused by the temperature difference between the two ends of a homogeneous conductor. The contact potential is the potential formed when two different conductors A and B are in contact, because of the different free electron density of the two conductors A and B, the electron diffusion occurs at the contact point. The contact potential is not only a function of temperature T, but also its contribution to the thermoelectric potential is far greater than the thermoelectric potential
The thermoelectric potential of thermocouple caused by temperature change is measured. According to the functional relationship between thermoelectric potential and temperature change, the temperature value causing thermoelectric potential can be known

According to what principle is a laboratory thermometer made

It is made according to the principle of thermal expansion and cold contraction of temperature measuring liquid

What is the principle of the thermometer in the laboratory?
emergency

There are many kinds of thermometers, most of which are based on the principle of thermal expansion and cold contraction

What is the principle of measuring the density of a substance in a laboratory

Density is equal to mass divided by volume
It must have been to our physics teacher today

Principle of electromagnetic relay control circuit
It's a question in the science book of grade two of junior high school in Shenzhen. It's a discussion on page 112

That answer is stupid
Textbooks have original answers
Is: the use of low voltage, weak current to control high voltage, strong current
There is this passage in the textbook, which is about the content

The working principle of electromagnetic relay in application is very important
It's the magnetic effect of the current
Effect of magnetic field on current
Thermal effect of electric current
Or the interaction between magnetic poles?

It is the magnetic effect of current, which controls the opening and closing of high-voltage line through low-voltage circuit. Because the direct opening or closing of high-voltage line will be dangerous to people who operate directly, there is electromagnetic relay. It uses the magnetic field generated by low-voltage coil to replace the direct effect of people

How to draw electromagnetic relay in circuit diagram
ditto

Km (coil end and switch end) in the figure is relay km

Working principle and wiring diagram of electromagnetic relay

Electromagnetic relay is a kind of electronic control device, which has control system (also known as input circuit) and controlled system (also known as output circuit). It is usually used in automatic control circuit. In fact, it uses smaller current and lower voltage to control larger current and higher voltage

What is the definition of magnetic effect of current?
555555 ~ the teacher left the review notes in the school. The book is not detailed enough. How to define it? Urgent

Definition of current magnetic effect
definition
Magnetic effect of electric current (electricity will produce magnetism): Auster found that any wire with electric current can produce magnetic field around it, which is called magnetic effect of electric current, The effect is the same as the magnetic field established by magnet. The magnetic field is generated around the long straight wire with current. There will be a magnetic field around the long straight wire with current. The shape of the magnetic induction line is a closed concentric circle with the wire as the center, and the direction of the magnetic field is perpendicular to the direction of the current
Right hand rule 1
Hold the wire with your right hand and point your thumb to the direction of the current (so it must be direct current. The direction of the current flows from the positive pole to the negative pole in the wire). The direction pointed by the other four fingers is the direction of the magnetic line of force or the direction of the magnetic force on the N pole of the magnetic needle
Right hand rule 2
Hold the coil with your right hand, four fingers point to the direction of the current on the wire, then the thumb is the direction of the magnetic line of force
Intensity of magnetic field 1
H (Gauss) = 2I (ampere) / 10R (CM)