Heat and Temperature

Thermometer is a device, which is used to measure the temperature.

Heat is a form of energy because heat is produced by the utilization of energy.

The basic function of a clinical thermometer is to measure the temperature of body.

The upper range of temperature in Fahrenheit sale is 108^oF.

The normal human body temperature is 37^oC or 98.6^oF.

To get accurate results, the level of mercury before placing the thermometer under the tongue, should be below 35^oC.

Conduction is the primary mode of heat transfer in solids.

conversion of steam to solid form is not an effect of heating. It is an effect of cooling.

Electricity is not a mode of heat transfer as it is a form of energy. It is the flow of electrons.

Laboratory thermometer is used to measure temperature of hot water. Commonly available laboratory thermometer are:

(i) Mercury thermometer            (ii) Bimetallic strip thermometers.

Ice will melt least in wooden box. It is because wood is a poor conductor of heat which does not allow heat to pass through them easily.

The range of laboratory thermometer is - 10^oC to 110^oC. For e.g. the range of mercury in glass is - 10^oC to 110^oC.

Tea is generally served in China clay cups as they are bad conductor of heat, that prevents the lips from heat of  tea, which is more sensitive than tongue.

Heat radiations from the furnace make one feel warm while standing beside its as the hot objects emit radiant energy. When falls on other objects, it is partially reflected and partly absorbed. The part that is absorbed increases the energy of the objects and makes one feel warm.

Paper is made of wood, which is an insulator and not a good conductor of heat. Glass is an insulator, which does not allow the heat energy to flow through it easily. So, paper and glass are bad conductors of heat.

Materials which allow heat to flow through them are called good conductor of heat. For e.g. Copper and aluminium are good conductors of heat.

Copper is good conductor of heat as copper allows heat to pass through it and conducts heat faster.

Spoon containing boiled milk is hot as energy transfers from a body at higher temperature to a body at lower temperature. Boiled milk is at higher temperature and spoon is at lower temperature. Wood is an insulator as it does not conduct heat. So, it does not become hot. After energy transfer takes place, the spoon becomes hot or warm.

Mercury is the toxic metal which is present in a clinical thermometer.

Maximum-minimum thermometer is related to weather report. It is used to measure the temperature of air, maximum and minimum temperature of the day, etc.

Radiation is the form of heat transfer that can occur in the absence of a medium. Thus, it is possible to transfer heat in vacuum through the process of radiation.

Temperature is defined as the degree of hotness or coldness of a body.

Kink prevents the level of mercury from falling down on its own. Kink is present near the bulb in a clinical thermometer.

When water is taken in a flask and is heated from the bottom then, by the process of convection, water gets heated in this experiment. When it is heated, the water near the flame becomes hot and this hot water rises up at the surface of the flask. The cold water from the sides moves down towards the source of heat and becomes hot and starts rising up. This process continues till the whole water gets heated. Thus, the heat is transferred to the entire volume of water through the movement of water molecules. This process of the hotter fluid moving and transferring heat to the colder surroundings is called convection.

The temperature range of a clinical thermometer is 35^oC to 42^oC. It is because the clinical thermometer is designed to measure the temperature of a human body only. The temperature of the human body normally does not go below 35^oC or above 42^oC.