Write the types of errors in the measurement of a physical quantity and explain them.

(N/A) Errors in the measurement of physical quantities are categorized as follows:
$(a)$ Systematic Error
$(b)$ Random Error
$(a)$ Systematic Error:
Systematic errors are those that tend to be in one direction,either positive or negative. These errors arise from known sources.
$(i)$ Instrumental Error: These arise due to imperfect design or calibration of the measuring instrument,or zero error in the instrument. For example,a thermometer may be inadequately calibrated,reading $104^{\circ}C$ instead of $100^{\circ}C$ at $STP$.
$(ii)$ Imperfection in Experimental Technique or Procedure: These occur due to flaws in the experimental setup. For example,if a thermometer is not placed in proper contact with the body,it will not measure the actual temperature.
$(iii)$ Personal Error: These arise due to individual bias,lack of proper setting of the apparatus,or carelessness. For example,parallax error occurs if the observer's head is not positioned correctly while reading a scale.
Systematic errors can be minimized by improving experimental techniques,selecting better instruments,and removing personal bias.
$(b)$ Random Error:
Errors that occur irregularly and randomly with respect to sign and size are called random errors. These arise due to unpredictable fluctuations in experimental conditions (e.g.,temperature,voltage supply). For example,if the same person repeats an observation,they may get different readings each time. These can be positive or negative and are minimized by taking the arithmetic mean of a large number of observations.