UPSC NDA I 2021 General Ability Solved Paper

CONCEPT: - Temperature: A physical quantity that measures the degree of hotness or coolness of the body is known as Temperature. - Temperature is measured in Celsius $(^{\circ}\mathrm{C})$, Fahrenheit $(^{\circ}\mathrm{F})$, and Kelvin. - Absolute temperature Scale:The Kelvin scale is an absolute temperature scale. When the temperature is measured in Kelvin. - This means that the theoretically lowest possible temperature is assigned the value of zero. - Absolute Zero: Zero degrees on the Kelvin scale is known asabsolute zero i.e. $0\,\mathrm{K}$. - It is theoretically the point at which there is no molecular motion to produce thermal energy. - Degree Celsius and Kelvin are the standard units of the temperature. - The relation between Degree Celsius and kelvin is givenby: $\Rightarrow K = C + 273.15^{\circ}\,\mathrm{C}$ EXPLANATION: Absolute temperature, $K = 0$ kelvin $\Rightarrow K = C + 273.15^{\circ}\,\mathrm{C}$ $\Rightarrow C = 0 - 273.15 = -273.15^{\circ}\,\mathrm{C}$ $\Rightarrow C = -273.15^{\circ}\,\mathrm{C}$ - Absolute zero temperature is 0 Kelvin temperature. -Each division in the kelvin scale called a kelvin $(K)$ is equal to a degree on the celsius scale, but the difference is where zero is. - On the Celsius scale, 0 degrees is the freezing point of water while in the Kelvin scale the zero points are atabsolute zero. - Therefore, $0\,\mathrm{K}$ is equal to -273.15 C, $0\,\mathrm{C}$ is equal to $273.15$ kelvins.