Note on Heat and temperature

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Heat

Heat is the sum of kinetic energy of all molecules of a substance. We use the expressions of hot and cold in our daily life on a number of occasions. We use heat for cooking food and keeping our body warm. We can get heat from coal, gas or electricity and sun. The degree of hotness and coldness of an object is called its temperature. Temperature is usually measured in the Celsius scale or Fahrenheit. The normal human body temperature is 98.40 Fahrenheit or 36.90 Celsius.

Temperature

Temperature is a measure of how hot or cold a body is. Temperature is usually measured in the Celsius scale or Fahrenheit scale. Temperature of the system can be defined as the property that determines whether or not the body is in thermal equilibrium with the neighbouring system. If the number of systems is in thermal equilibrium, this common property of the system can be represented by the simple numeric value called temperature.

Differences between Heat and Temperature

The differences between heat and temperature can be summarised in points as follows:

S.N Heat S.N Temperature
1. Heat is the form of energy that flows from the system to its surroundings. 1. Temperature is the result of heat.
2. Mass of the body affects the total heat. 2. Mass of body does not effect on temperature but depends on the molecular vibration of the body.
3. Heat is measured in joules or calories.

4.2 Joules = 1 calorie

3. Temperature is measured in degree Celsius or degree Fahrenheit or Kelvin Scale.
4. Heat is measured by using a Calorimeter. 4. Temperature is measured using the thermometer.

  • Heat is the sum of kinetic energy of all molecules of a substance.
  • We use heat for cooking food and keeping our body warm.
  • We can get heat from coal, gas or electricity and sun.
  • The degree of hotness and coldness of an object is called its temperature.
.

Very Short Questions


S.No.
Heat Temperature
1 Heat is a kinetic energy of all molecules of a substance. Temperature is the degree of hotness and coldness of a body.
2 Its SI unit is joule. Its SI unit is Kelvin.

 

The two common scales of the temperature are the Celsius scale and the Fahrenheit scale.

The temperature of pure melting ice and that of steam on the Celsius scale is 0 degree centigrade to 100 degree centigrade. 

\begin{align*}\frac {(K-273)}{100}= \frac {(C-0)}{100} \\ \text {or,}\: (100 – 273) &= C \\ \text {or,}\: C &= -273 + 100 \\ \text {or,}\: C &= -173 \\ \text {Thus,}\: 100\:K &= -173^o\:C. \\ \end{align*}

\begin{align*} \frac {(C – 0)}{ 100} &= \frac {(K- 273)}{100} \\ \text {or,}\: 220 &= K-273 \\\text {or,}\: K &= 273 + 220 \\ K &= 493 \\ \text {Thus} \: 220^o\:C &= 493\: K \\ \end{align*}

\begin{align*}\frac {(C-0)}{100} &= \frac {(F-32)}{ 180} \\\text {or,}\: \frac {30}{10} &= \frac {(F-32)}{18} \\\text {or,}\: 30 \times 18 &= (F – 32) \times 10 \\ \text {or,}\: 540 &= 10F – 320 \\ \text {or,}\: 540 + 320 &= 10F \\ \text {or,} F = \frac {860}{10} \\ \text {Thus}\: 30^o\:C &= 86^o\:F \\ \end{align*}

One calorie is the amount of the heat required to raise the temperature of one gram of water by 1°C.

$$ \frac {(C – 0)}{100} = \frac {(F – 32)} {180} = \frac {(K – 273)} {100}$$

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  • Unit of heat is ______.

    degree


    Joule


    kilogram


    meter


  • Device used for measuring temperature is ______.

    Speedometer


    Thermometer


    Odometer


    Barometer


  • The hotness on an object is determined by its ______.

    none of these


    temperature


    heat


    pressure


  • The temperature of boiling water cannot be measured by ______.

    All the answers are correct


    both clinical and laboratory thermometer


    clinical thermometer


    laboratory thermometer


  • A wooden spoon is dipped in a cup of ice cream , its other end ______.

    does not become cold


    becomes cold by the process of radiation


    becomes cold


    becomes hot


  • The boiling point of water is ______.

    100°C


    357°C


    0°C


    39 °C


  • Higher the temperature of the body ______ the kinetic energy of the molecules of that body.

    none of these


    Higher


    Same


    Lower


  • What happens to the object when heat energy is supplied to it?

    the molecules of the object moves faster
    all the answers are correct
    the molecules gets far apart from each other
    the object gets hot
  • The device that measures the degree of hotness and coldness of a body is called ______.

    calorimeter


    thermometer


    lactometer


    temperaturemeter


  • Which is the most commonly used liquid in the thermometer?

    ethanol


    water


    alcohol


    mercury


  • Process of division of temperature scale in thermometer is called ______.

    marking of thermometer


    division of thermometer


    separation of scale in thermometer


    calibration of thermometer


  • The advantages of using mercury in a thermometer is ______.

    it does not stick in the glass


    it can be used to measure wide range of temperature


    the calibration of mercury is easier as it expands uniformly at ordinary temperature


    all of the answers are right


  • Clinical thermometer was invented by ______.

    Graham Bell


    Sir Isaac Newton


    Sir Arthur King


    Sir Clifford Allbutt


  • Clinical thermometer was invented in _______.

    1890 A.D.


    1850 A.D.


    1860 A.D.


    1870 A.D.


  • The thermometer used to measure the maximum and minimum temperature of a day is called ______.

    day and night thermometer


    horse shoe thermometer


    clinical thermometer


    maximum and minimum thermometer


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What is one joule heat


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Santosh Sharma

What is one calorie


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ranjan

relatiionship betn heat and tempreature


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