# Young's doublt slit experiment - Systematic and random errors - !

1. Aug 9, 2011

Young's doublt slit experiment - Systematic and random errors - URGENT!

1. The problem statement, all variables and given/known data

Can anybody think of any other systematic and/or random errors for young's double slit experiment when using it calculate the wavelength of a light source? I have an inclass prac write up tomorrow and i can't think of any others, if you guys can think of any THEN PLEASE HELP, THANKS!

3. The attempt at a solution

Random
1. Parallax error – distance from cross hairs to screen -
2. Parallax error – reading from vernier caliper
3. Widely spaced fringes of light of interference
4. Light entering from beneath cloth – interference - lower intensity light – less precise measurement
Systematic
1. Formula depends on the angular separation of the double slits to be extremely small, <<1 degree – so it is an approximation, hence an error

2. Aug 9, 2011

### PeterO

Re: Young's doublt slit experiment - Systematic and random errors - URGENT!

Wikipedia gives the following hint:
Measurement errors can be split into two components: random error and systematic error.[1]

Random error is always present in a measurement. It is caused by inherently unpredictable fluctuations in the readings of a measurement apparatus or in the experimenter's interpretation of the instrumental reading.

Whereas, systematic errors are predictable, and typically constant or proportional to the true value. If the cause of the systematic error can be identified, then it can usually be eliminated. Systematic errors are caused by imperfect calibration of measurement instruments or imperfect methods of observation, or interference of the environment with the measurement process, and always affect the results of an experiment in a predictable direction. Distance measured by radar will be systematically overestimated if the slight slowing down of the waves in air is not accounted for. Incorrect zeroing of an instrument leading to a zero error is an example of systematic error in instrumentation.