Temperature and its Measurement — Important Questions

Hold the thermometer vertically, Read temperature while thermometer is in water, Keep eye level with liquid column

Correct usage includes holding vertically, reading while immersed, and keeping eye level with the liquid column. The bulb should not touch container walls/bottom, and tilting gives wrong readings.

Touch can be unreliable and misleading

Our sense of touch can be misleading because it depends on the previous temperature our hands were exposed to. The same water can feel warm or cold to different hands.

kelvin

Kelvin (K) is the SI unit of temperature. Note that it's written as 'kelvin' (lowercase) and doesn't use the degree symbol (°).

They are safer than mercury thermometers, They run on batteries, They show temperature digitally

Digital clinical thermometers are safer than mercury ones, run on batteries, and display temperature digitally making them easy to read. They don't contain mercury.