Heat and Temperature


 
 
Concept Explanation
 

Heat and Temperature

Heat is the transfer of energy from a hot body.

The sense of touch can be used to understand the degree of hotness or coldness of something. But the sense of touch is not reliable and cannot be always used to say how much hot anything is. Moreover, using the sense of touch can be risky in case of something very hot. Thus, hotness of anything is measured in terms of Temperature in reliable way. To measure temperature a device called Thermometer is used.

  • Temperature:  Temperature is defined as the degree of hotness or coldness of a given body or an environment.
  • Thermometer: A device used for measuring temperature of any object/body.
  • Unit of heat: There are three units which are used to measure the temperature. Degree Celsius, Fahrenheit and Kelvin.
  • Degree Celsius: Degree Celsius is written as °C and read as degree Celsius.
  • Fahrenheit: Fahrenheit is written as °F and read as degree Fahrenheit.
  • Kelvin: Kelvin is written as K. For example 100 K; it is read as hundred Kelvin.
  • Conversion from one scale to another:

    K= C + 273    

    C=frac{5}{9} (F-32)

    Difference between Heat and Temperature

    Heat

    Temperature

    It is a form of energy.

    It is the degree of hotness or coldness of a body.

    Heat causes a change in the temperature of a body.

    It is the effect of heat.

    It is measured in joules or calories.

    It is measured in degree Celsius or degree Fahrenheit.

    Conversion of temperature from one scale to another scale.

    Whatever may be the scale of temperature used form experiments it is concluded that,

    frac{Thermometer;Reading -Lower;fixed;point}{No.;of;divisions}=constant

    i.e., frac{Temperature;one;scale-Lower;fixed;point}{Upper;fixed;point-Lower;Fixed ;point}

    =frac{Temperature;on;another;scale-Lower;fixed;point}{Upper;fixed;point-Lower;fixed;point}

    =frac{C-0}{100-0}=frac{F-32}{212-32}=frac{K-273}{273-273}

    Illustration: For a faulty thermometer upper and lower points are found to be 98^{circ}C and -2^{circ}C respectively. What is the correct temperature if this thermometer reads 38^{circ}C?

    Solution: 

    frac{C-0}{100}=frac{R-LFP}{UFP-LFP}Rightarrow frac{C}{100}=frac{38+2}{98+2}Rightarrow C=40^{circ}C

    Sample Questions
    (More Questions for each concept available in Login)
    Question : 1

    The measure of how hot or cold something is _____________

    Right Option : C
    View Explanation
    Explanation
    Question : 2

    Temperature is measured by ________ .

    Right Option : B
    View Explanation
    Explanation
    Question : 3

    __________________ a device used for measuring temperature of any body.

    Right Option : A
    View Explanation
    Explanation
     
     
     


    Students / Parents Reviews [10]