What is Difference Between Systematic error and Random error ?

Difference between Systematic Error and Random Error:

Sr. No.	Systematic Error	Random Error
1.	These errors results due to improper method of measurement or incorrect use of apparatus.	Error occurs due to Environment, limitation in measuring Instrument.
2.	Consistent and Repetitive in nature.	These are sudden and accidental type
3.	Appears in one direction	Occurs in both the directions.
4.	All errors can be minimized in magnitude and sense, except human error.	Magnitude and sense of error cannot be controlled.
5.	Magnitude is constant.	Magnitude varies
6.	Error cannot minimized by statistical method.	Error minimized by statistical method by repeatedly taking the reading.
7.	Errors can be recognized and reduced, if readings taken are analyzed.	It cannot be Eliminated but results achieved can be corrected.
8.	It consists of, Environmental conditions, variation in contact pressure, Calibration error.	It  consists of, Operator error, Fluctuation in setting the standard and work-piece, Error in reading scale, fluctuation due to friction in measurement.

What is difference between Torque and Moment?

Difference between Torque and Moment:

Sr. No.	Torque	Moment
1.	It is measure of turning force of the object	It is perpendicular distance between point of rotation and line of action of the force.
2.	Denoted by symbol “τ”	Denoted by symbol “M”
3.	Shear stresses induced due to torque.	Bending or Flexural stresses produced due to Moment
4.	Coupling is Measured	Coupling is not Measured.
5.	It is movement Force	It is static Force
6.	It produces angular deflection.	It produces deflection i.e. vertical displacement of longitudinal axis.
7.	It is used when there is rotation.	It is used when there is no rotation.
8.	Applications: hinged doors, Wrench,	Applications: trees in wind

What is Difference between CPM and PERT ?

Difference between CPM and PERT:

Sr. No.	CPM	PERT
1.	It stands for Critical Path Method.	It stands for Program Evaluation and Review Technique.
2.	Used to control time and cost.	Used to control Time
3.	Activity focused technique	Event focused technique
4.	It is deterministic model used where occurrence of all events is known with certainty.	It is probabilistic model used where occurrence of events cannot perfectly predicted.
5.	Time required for each activity is known and defined for project.	Time is not much importance in this technique.
6.	It used for comparatively small projects.	I used for larger project.
7.	It uses single time estimate for carrying out of activity.	It uses three time estimate for carrying out of activity
8.	Suitable for Construction projects.	Suitable for Research and development, Investigation, Design.

What is difference between Soldering and Brazing ?

Difference Between Soldering and Brazing :

Sr. No.	Soldering	Brazing
1.	It is the method of joining two or more pieces of metal by means of fusible alloy or metal.	It is the method of joining similar or dissimilar metals by heating and melting filler between metals that joins them.
2.	Filler material in soldering also called as Solder. It is mostly composed of lead and tin.	Filler material in brazing also called spelter .It is composed of silver-base, copper-base alloys. Mostly brass is used as filler.
3.	Zinc chloride is used as flux.	Borax  is used as flux.
4.	Weaker joint than brazing	Stronger joint than soldering.
5.	It is done in the temperature range between 1500 c to 4000 c.	It is done in the temperature range between 6000 c to 8500 c.
6.	Skilled worker not required.	Skilled worker requires.
7.	Less costly.	Expensive.
8.	Preheating of base metal is not required.	Preheating of base metal is required.
9.	Mostly used in electrical, electronics industry.	Used in mechanical industry, pipe fittings, automobile.

What is difference between Accuracy and Precision?

Difference between Accuracy and Precision :

Sr. No.	Accuracy	Precision
1.	It is agreement of the measured value with standard  value of measured quantity.	It is repeatability of measuring process. Where in the set of measurement, results agrees with each other.
2.	It is concerned with true value.	Not concerned with true value.
3.	Difficult and costly to achieve high accuracy.	Easy and less costly.
4.	High accuracy cannot be achieved with low precision.	High precision can be achieved with low accuracy.
5.	It is associated with controllable or systematic error.	It is associated with random error.
6.	It is degree of conformity.	It is degree of reproducibility.
7.	Accuracy depends on single factor.	Precision depends on multiple factor.