Question

Write the SI units of luminous intensity and temperature.

Answer 1

Hint: First find and understand the definition of luminous intensity and temperature. Write the expressions for both in terms of those quantities whose SI units are known. Then calculate the units of luminous intensity and temperature.

Complete step-by-step answer:
Luminous intensity is defined as the luminous flux of light in one unit of solid angle. Luminous flux is the power (energy per unit time) of light emitted in one unit of area. Solid angle is a three-dimensional analogue of an angle such as that subtended by a cone. It is measured in steradians. The S.I unit of luminous flux is ${\displaystyle \frac{\text{watts}}{{\text{m}}^{\text{2}}}}$ called lumen. Therefore, the SI unit of luminous intensity is ${\displaystyle \frac{\text{lumen}}{\text{steradians}}}$ called candela.
Temperature is a quantity that defines the state of a substance (especially in gases). Temperature is a measurement of hotness and coolness of a body. We feel that a body is hot when its temperature is higher and when the temperature of a body is lower it feels colder. The SI unit of temperature is Kelvin. Other unit is degree Celsius.

Additional Information:
Temperature is one of the fundamental physical quantities. The relation between the Kelvin scale and the degree scale is as follows:
$T_C+273=T_K$, where $T_K$ is the temperature in kelvin and $T_c$ is the temperature in Celsius scale.
There are two more temperature scales known as Fahrenheit scale and Rankine scale. The relation between the four scales is as follows:
${\displaystyle \frac{C}{100}}={\displaystyle \frac{F-32}{180}}={\displaystyle \frac{K-273}{100}}={\displaystyle \frac{R-492}{180}}$
F, R, C and K are temperatures in Fahrenheit, Rankine, Celsius and Kelvin respectively.

Note: Sometimes we get confused between heat and temperature. As said temperature is a measurement of hotness or coldness. Heat is a form of energy. A body at higher temperature is hotter and it transfers energy to a colder body, which we call as heat.
Heat and temperature are correlated but not the same. The heat exchange depends on the temperature difference between the bodies.