Question

eg of least count of thermometer

Answer 1

Laboratory thermometer with different least counts are use for different measurement. Least count of a measuring instrument is the least value of physical quantity that can be measured accurately using the instrument. Generallythermometer having least count 1 0C or 0.5 0C are used in the laboratory.

Answer 2

it is called Absolute zero. Temperature is the vibration of atoms, and at absolute zero they stop vibrating all together. 

Absolute Zero is: −273.15° Celsius or −459.67° Fahrenheit