Activity 4.2 heat science class 7 chapter 4
Answer:
A clinical thermometer measures the temperature between 35ºC to 42ºC. Its mercury level expands on an increase in temperature. We see this rise as a temperature level.
We should first clean the thermometer using soap or sanitizer and shake it vigorously so that mercury level drops below 35ºC. Then we should place it below the tongue for 2-3 minutes. During this time mercury level rises as per the body temperature. Now, we should put the thermometer in front of the eye and should examine it throughly.
A mercury thermometer has linings between the two points. If the two-point have a one-degree difference, and between them, there are ten lines, then one line indicates 0.1ºC.
fact:
Nowadays, clinical thermometers are being replaced by digital thermometers. Digital thermometers have a digital sensor that measures the temperature and shows the exact temperature as an exact value.
Next: Activity 4.3 Heat.
See also: Activity 4.1 Heat.
Paheli Boojho Answer Chapter 4 Heat.
Exercise Solution Heat Class 7 Science Chapter 4.
Ref: NCERT.
