Question

What is the use of kink in a clinical thermometer?

Answer 1

Hint:Firstly, we have to know what clinical thermometers are. Clinical thermometers are the same as medical thermometers used for measuring the animal or human body temperature. In the question we are asked for the use of kink in the thermometer for that we should know the actual construction of the thermometer.

Complete answer:
The temperature of an object is defined as the degree of hotness of the object. The instrument used to measure temperature is known as a thermometer. Thermometer has a Celsius sale $\left( {^\circ C} \right)$ marked on it used to read the temperature. There are two types of thermometers:
-Clinical thermometers
-Laboratory thermometers

Clinical thermometers:
The thermometers which are used to measure the temperature of the human body. A clinical thermometer consists of a long glass tube having a glass bulb at its one end and the other end is sealed. The glass bulb has mercury inside it. Glass tube has a Celsius scale marked on it. It also has a kink (or constriction) in the glass tube just above the bulb containing mercury. The kink is to prevent back flow of mercury into the thermometer bulb when the thermometer is removed from the mouth of the patient. The kink prevents the mercury level from falling so that we can read the temperature of the patient carefully.

Note:Clinical thermometers have a very short range of temperature from $35^\circ$ to $42^\circ C$. Before using the thermometer, we should ensure that the mercury level is below $35^\circ C$ mark. With the clinical thermometer, we can measure the one-tenth temperature of a human body.