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If the true value of a certain length is 3.678 cm and two instruments with different resolutions , up to 1 ( less precise ) and 2 ( more precise ) decimal places respectively , are used . If first measures the length as 3.5 and the second as 3.38 then the first has more accuracy but less precision while the second has less accuracy and more precision .
Types of Errors- Systematic Errors
Errors which can either be positive or negative are called Systematic errors . They are of following types :
1 . Instrument errors : These arise from imperfect design or calibration error in the instrument . Worn off scale , zero error in a weighing scale are some examples of instrument errors .
2 . Imperfections in experimental techniques : If the technique is not accurate ( for example measuring temperature of human body by placing thermometer under armpit resulting in lower temperature than actual ) and due to the external conditions like temperature , wind , humidity , these kinds of errors occur .
3 . Personal errors : Errors occurring due to human carelessness , lack of proper setting , taking down incorrect reading are called personal errors .