Uncertainties in physics experiments and measurement and their solutions?

Uncertainties:-

Uncertainty is the situation which involves imperfect  or unknown  information.

There are three kinds of uncertainties commonly known today.

I)Absolute uncertainty

ii)Fractional uncertainty

iii)Percentage uncertainty

i)Absolute Uncertainty:-

• ·         Usually called absolute error

• ·         Usually the range of values in which the” true value” lies.

• ·         It is related to the least count of the measuring instrument.

• ·         Has the same unit as that of the value.

Least Count of the some measuring instrument is given as;

i)                    L.C of Meter Rod is 0.1cm

ii)                   L.C of Vernier  caliper is 0.01cm

iii)                 L.C of Screw Gauge is 0.001cm

Precision:-

• It is the minimum value that the device can measure.

• A device with less precision is more precise

e.g :Screw Gauge has least precision ,so it is more precise device

ii)Fractional Uncertainty:-

• ·         Also known as percentage uncertainty

• ·         It is the ratio of L.C to the mean value or measured value

• ·         It has no unit

Formula:-

Fractional Uncertainty= L.C/M.V

iii)Percentage Uncertainty:-

The percentage uncertainty can be interpreted as describing the uncertainty that would result if the measured value had been 100 units.

• ·         It has no units

• ·         It is the ratio of L.C to the mean value or measured value multiply by 100

Formula:-

Percentage Uncertainty= L.C/M.V * 100

Errors in physics experiments and measurement and their solutions?

a)Errors

 The difference between standard and experimental values is error.

There are two types of errors:-

i)Systematic error

ii)Random error

i)Systematic error :-

• ·         Also known as assignable error

• ·         Usually follow same trend of variations

Causes:-

• ·         Zero error in measuring instrument

• ·         Poor calibration of instrument

• ·         Incorrect calibration on the measuring instrument

EXAMPLE:-

Error occurring due to L.C of the measuring instrument

SOLUTION TO SOLVE ERROR:-

• ·         By comparing the instrument with other instrument which is more accurate

• ·         By carefully monitoring the measurement process

ii)Random error:-

• ·         Also known as Un Assignable error

• ·         Do not follow the same trend of variation

Causes:-

• ·         Due to some unknown reasons

• ·         Deviation in results

EXAMPLE:-

During measurement ,there are different  values of result of same measuring quntity.

SOLUTION TO SOLVE ERROR:-

• ·         Cannot be controlled experimentally.

• ·         By taking several reading of same measuring quantity  and then taking their mean value.

Errors and Uncertainties in physics experiments and measurement and their solutions?

a)Errors

The difference between standard and experimental values is error.

There are two types of errors:-

i)Systematic error

ii)Random error

i)Systematic error :-

• ·         Also known as assignable error

• ·         Usually follow same trend of variations

Causes:-

• ·         Zero error in measuring instrument

• ·         Poor calibration of instrument

• ·         Incorrect calibration on the measuring instrument

EXAMPLE:-

Error occurring due to L.C of the measuring instrument

SOLUTION TO SOLVE ERROR:-

• ·         By comparing the instrument with other instrument which is more accurate

• ·         By carefully monitoring the measurement process

ii)Random error:-

• ·         Also known as Un Assignable error

• ·         Do not follow the same trend of variation

Causes:-

• ·         Due to some unknown reasons

• ·         Deviation in results

EXAMPLE:-

During measurement ,there are different  values of result of same measuring quntity.

SOLUTION TO SOLVE ERROR:-

• ·         Cannot be controlled experimentally.

• ·         By taking several reading of same measuring quantity  and then taking their mean value.

Uncertainties:-

Uncertainty is the situation which involves imperfect  or unknown  information.

There are three kinds of uncertainties commonly known today.

I)Absolute uncertainty

ii)Fractional uncertainty

iii)Percentage uncertainty

i)Absolute Uncertainty:-

• ·         Usually called absolute error

• ·         Usually the range of values in which the” true value” lies.

• ·         It is related to the least count of the measuring instrument.

• ·         Has the same unit as that of the value.

Least Count of the some measuring instrument is given as;

i)                    L.C of Meter Rod is 0.1cm

ii)                   L.C of Vernier  caliper is 0.01cm

iii)                 L.C of Screw Gauge is 0.001cm

Precision:-

• It is the minimum value that the device can measure.

• A device with less precision is more precise

e.g :Screw Gauge has least precision ,so it is more precise device

ii)Fractional Uncertainty:-

• ·         Also known as percentage uncertainty

• ·         It is the ratio of L.C to the mean value or measured value

• ·         It has no unit

Formula:-

Fractional Uncertainty= L.C/M.V

iii)Percentage Uncertainty:-

The percentage uncertainty can be interpreted as describing the uncertainty that would result if the measured value had been 100 units.

• ·         It has no units

• ·         It is the ratio of L.C to the mean value or measured value multiply by 100

Formula:-

Percentage Uncertainty= L.C/M.V * 100