Table of Contents
Definition – Temperature
The common conceptions of hot and cold have evolved into the concept of temperature. The sense of what is cold or hot is subjective. For instance, if you put one hand in hot water and the other in cold water, then put both hands in tepid water, the tepid water will feel cool to the hot water hand and warm to the cold-water hand. Your senses of heat and cold are less vague than the scientific concept of temperature. The operational definition of temperature is what we can measure with a thermometer. Two accurate thermometers, one in hot water and the other in cold water, will reveal that the hot water is hotter. When both are submerged in tepid water, they will provide identical results.
Overview on Temperature
A thermometer can be made out of any physical attribute that is affected by temperature and has a repeatable response to temperature. Because temperature affects so many physical attributes, thermometers come in a wide range of shapes and sizes. Electrical resistance, color, and the emission of infrared light are some of the other qualities used to measure temperature. A plastic thermometer is an instance of electrical resistance and color. The usage of a pyrometer provides an example of radiation emission. A temperature readout is easily made by measuring infrared radiation (whose emission fluctuates with temperature). The use of infrared measurements to determine body temperature is also common. These new ear thermometers are more reliable than alcohol thermometers inserted under the tongue.
What is Absolute Zero?
Absolute zero is the smallest theoretical temperature at which no additional thermal energy can be collected from a body. The third law of thermodynamics recognizes that it can only be approached extremely precisely (100 pK) but not reached experimentally.
Temperature is significant in physics, Earth science, astronomy, health, biology, ecology, material science, metallurgy, mechatronics, and geography, as well as most elements of everyday life.
Formula and Evolution
Why are temperature conversion formulas required?
Temperatures are usually expressed as numerical values using specified units.
On different temperature scales, the same temp has different readings:
Fahrenheit, Celsius, and Kelvin are the three temperature scales.
The term “temperature conversion” refers to the process of transferring a temperature’s value from one scale unit to another.
It’s necessary so that we can compare different temperature measurements on the same platform.
There are several methods for converting temperatures:
- Water has a freezing point of 273.15K and a boiling point of 373.15K on the Kelvin scale.
- Water has a freezing point of 32°F and a boiling point of 212°F on the Fahrenheit scale.
- Water has a freezing point at a degree and a boiling point of 100°C on the Celsius scale.
There have been three main temperature conversions:
- The terms Celsius and Kelvin are used interchangeably.
- Fahrenheit and Kelvin are both temperature units.
- Temperatures in Celsius and Fahrenheit
Temperature is the amount or intensity of heat contained in a substance or system, as measured by a thermometer and stated on a comparative scale. Temperature, in other terms, is the measurement of a body’s hotness or coldness using the Celsius, Kelvin, and Fahrenheit scales.
The amount of heat produced or absorbed determines the temperature change. Kelvin is the SI-derived unit of temperature.
Temperature Formula and Units
The formula for temperature is as follows:
T = Q / mc
Where,
T = difference in temperature,
The amount of heat absorbed is denoted by the letter Q.
m is the body’s mass,
c is the body’s specific heat.
Temperature inversion
It is referred to as thermal inversion, is a reversing of typical temperature behavior in the troposphere (the part of the atmosphere closest to the Earth’s surface) in which a layer of chilly earth’s atmosphere is overlain by a layer of warmer air.
Cloud cover, rainfall, and sight are all influenced by inversions. The upward flow of air from the layers underneath is slowed by an inversion. As a result, convection caused by below-inversion heating is confined to levels below the inversion. Dust, pollution, and other air pollutants are also limited in their spread. Convective clouds cannot develop high enough to create showers in places where a substantial low-level inversion exists, and vision below the inversion may be greatly impaired, even in the absence of clouds, caused by the accumulation of dust or smoke particles. Fog is typically prevalent towards the base of such an inversion because the air is cold.
Ground, turbulence, subsidence, and frontal inversions are the four types of inversions:
- When air is cooled by contact with a colder surface, it becomes cooler than the surrounding atmosphere; this happens quite often on clear nights when the ground cools off quickly due to radiation.
- As quiescent air overlies turbulent air, a turbulence inversion occurs. Vertical mixing inside the turbulent layer transports heats downwards and cools the top part. The unmixed air above does not cool, and it eventually becomes warmer than the air below, resulting in an inversion.
- When a large layer of air falls, it creates a subsidence inversion. As a result of the increased air pressure, the layer is compressed and heated, and the lapse rate of temperature is diminished.
- When a cold air mass undercuts a warm air mass and lifts it aloft, a frontal inversion occurs; the front between both the two air masses then has warm air above and cold air below. This type of inversion has a steeper slope than others, which are virtually level. Furthermore, humidity levels may be high, and clouds may be present just above it.
The thermal expansion features of mercury are used in old-fashioned glass-bulb thermometers to detect temperature. When Mercury is warm, it expands, and when it is chilly, it contracts. As the mercury expands, it climbs inside the glass tube, making it possible to measure it. The principle of thermal expansion is also used by spring thermometers, which have a circular face with a metal pointer. They have a coiled metal piece within that expands and cools in response to temperature, enabling the pointer to move. Heat-sensitive liquid crystals are used in digital thermometers to initiate digital temperature displays. Infinity Learn has supplied thorough notes on the topic of temperature, which covers everything from the basic concept of temperature and heat to the differences between them and various thermometers. These notes were written by physics professors for your better comprehension of the subject. You can also learn about temperature and its importance in today’s society by attending an infinity learn online course, in which you can ask subject specialists questions and obtain a thorough understanding of the themes. Experts also present questions at the end of each topic to assess your understanding.
Significance of Temperature in NEET exam:
This article on temperature provides comprehensive information on the numerous types of temperature scales. Examine the detailed notes attentively to ensure that you understand this topic since it will help you prepare for the next NEET exam. You can also jot down some brief notes on the temperature to reference during the exam.
The NEET topics are designed to address and clarify the most common questions on the exam. These can be expressed in simple words with the help of notes from competent researchers in the field, which are posted on the Infinity Learn online platform. Multiple-choice questions are easy to practice if students have a good understanding of the subjects presented throughout the program.
FAQs for Temperature
What is the relation between temperature and hotness?
Although temperature and heat are two distinct ideas, they are linked. Temperature is a measurement of the body's hotness; as the hotness grows, the body's temperature increases accordingly. When the body's molecules gain kinetic energy, the body heats up. More information on this topic may be found on the infinite learn website, or you can use the Infinity learn learning app to discover more about temperature.
When the water boils, what temperature does it reach?
The water is at a temperature of 100 degrees Celsius when it boils. It's the temperature or atmospheric pressure at sea level. The boiling point of water varies depending on the air pressure, which varies with elevation.
On the Kelvin scale, what is the lowest temperature?
On the Kelvin scale, the lowest temperature is zero (0) kelvin or -273.15ͦ c on the Celsius scale. That is why it is known as absolute zero, which is extremely difficult to attain. There is no heat in the body at absolute zero; the particles there are stationary, and the kinetic energy that provides heat is zero.
