Tag: geography

In modern thermometer, mercury is used as it is a reflective liquid. It is bright and opaque, so it’s easy to see movement of mercury inside the capillary tube and to read accurately. Even mercury does not wet the glass. So, if temperature is falling then you do not get inaccurate readings. It is also good conductor of heat. So, it reacts quickly to change in temperature.

• Thermogram is an instrument which is used for creating images based on heat radiation emitted from any object. It has many applications ranging from medical settings to weather stations. Hence A is the correct option.
• The thermometer measures the temperature of the human body.
• Isotherms are the lines joining various points on the map having the same temperature during a given period. Hence B and C are incorrect.

Mean daily temperature is the average temperature in each period of 24 hours. It is measured at 1.5 meters above ground level. Mean daily temperature can be determined by finding out the mean of maximum and minimum temperature of a day.

A Thermogram is a modern instrument that continuously measures and records the temperature and is used in weather stations. It provides information in form of a graph called thermograph.

Thermographs are a good alternative to the digital collection of data. The thermographs are equipped with mechanical or quartz clockwork. Easily it can be switched from weekly recording to daily or monthly recording. They will be delivered with writing pens and a recording paper.

A line on a map connecting places with the same temperature at a given time is known as isotherm. Isotherms are created from regularly scheduled, simultaneous temperature readings at different locations. It shows patterns of temperature on a weather map. It helps in visualizing and interpreting horizontal temperature distribution of an area. The elementary step in temperature data analysis is construction of isotherm maps.

Thermometer is a device which is used to measure temperature. There are two reference points marked on a thermometer. One reference point represents freezing point of water. Freezing point of the water is the temperature at which water starts converting into ice. As per Celsius scale, zero degree is the freezing point of the water. Other reference point represents boiling point of water. Boiling point is the temperature at which water starts converting into vapours. As per Celsius scale, 100 degree is the boiling point of the water.

The mean annual range is an indicator of the variation among the monthly temperature in a year. It is calculated by taking the difference between the highest and lowest mean monthly temperature recorded in a year.

To measure the minimum and maximum temperature in a day, Six’s thermometer is used.  It consists of a U-shaped capillary tube having bulbs at both ends. Mercury is filled in the bend of the U-tube. One of the bulbs is completely filled with alcohol and the other bulb is partly filled with alcohol. Alcohol is the thermometric liquid in case of Six’s thermometer. Change in temperature is recorded due to expansion and contraction of alcohol.

Mean Annual Temperature: The average temperature for the entire year at any given location.

$\dfrac{\Sigma {(\text{Mean monthly temperature})}}{12}$