Question

why is it advised not to hold the thermometer by its bulb while reading it?​

Answer 1

$\huge\underline\mathfrak\red{Answer}$

⚡It is advised not to hold the thermometer by its bulb while reading it because this will increase the temperature of mercury than its actual temperature and this will result in slightly wrong reading.

⚡To be precautious it is advised not to do so.

Answer 2

Answer:

If we hold a thermometer by its bulb, the mercury in the bulb will expand

due to our body temperature.