Page 35 - Science Class 07

degree (0°C) and the temperature at which 100 equal divisions. Each such division
pure water boils at under normal atmospheric measures a temperature difference of 1°C (one
pressure is taken to be 100°C. The separa on degree celsius).
between these two fixed points is divided into

Write the maximum and minimum temperature of four metro ci es of today from the
newspaper.

Ci es Max. Temp. Min.Temp.

Delhi

Mumbai

Kolkata
Chennai

The Fahrenheit Scale : On the Fahrenheit scale, You should remember that temperatures are
named a er Fahrenheit, these fixed points, i.e., expressed in ‘Kelvin’ and not degree Kelvin.
freezing point and boiling point are defined as Formulae:

32° F and 212° F respec vely and the
To convert Celsius into Kelvin K = C + 273
separa ons between them is divided into 180
divisions. To convert Kelvin into Celsius C = K – 273
The rela ons between Celsius (C) and Fahrenheit Thermometer

(F) temperatures are: Thermometers are the instruments designed to
Formulae: measure temperature. There are different kinds
of thermometers.
To convert Celsius into Fahrenheit:
Some of them are:
F = (C) 9/5 + 32
v Liquid – in – glass thermometer
To convert Fahrenheit into Celsius:
v Clinical thermometer
C = (F-32) 5/9
v Thermometers for industry
The Kelvin Scale : It was designed by William v Resistance thermometer
Thompson (Lord Kelvin) in 1848. This scale is
The Clinical Thermometer
also known as the absolute temperature scale.
In this scale, absolute zero is taken as Clinical thermometer is a slight modifica on of
mercury thermometer. It is specially designed
–273.16°C or –459.7°F. At absolute
to measure the human body temperature.
temperature, the movement of molecules of
body stops. Each Kelvin (K) on the scale is of

the same size as a degree celsius (°C), so
conversions from one scale to another is easy.

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