Tiêu đề 2nd stats ch 07.pdf ✅

Chapter 7 Statistical Quality Control One and Two Marks Questions With Answers Question 1. What do you mean by Statistical Quality Control? Answer: The control of quality of manufactured articles using statistical, techniques is called SQC. Question 2. Mention two types of causes for variation in a manufacturing process. Answer: Chance causes and Assignable causes. Question 3. In X̄ – chart, if one of the sample means lies outside the control lines, what would you conclude? Answer: We conclude that the production process is out of control’ or lack of control. Question 4. SQC helps in which type of variation?/ Which type of ’cause of variation’ is detected by SQC. Answer: SQC helps in detecting Assignable causes. Question 5. Which cause of variation cannot be eliminated from the process control? Answer: Chance cause of variation. Question 6. Distinguish between a defect and a defective/what are Defects and Defectives? Answer: • A defect is a quality characteristic, which does not conform to specifications. • The presence of one or more defects in a product/article is a defective.


Chapter 7 Statistical Quality Control The control of quality of manufactured products using statistical techniques is called statistical quality control. Question 21. What are chance causes? Answer: A small amount of variation in the quality of the product for no specific cause/reason, and such variation is called chance causes. Question 22. What are assignable causes? Answer: Variation in the quality of the product due to use of substandard raw material, improper machine setting, wrong handling of machines, power variation etc., and such variations are called assignable causes. Question 23. What is a control chart? Answer: Control chart is a graphical device which is used to verify whether the production process is in statistical control or not. Question 24. Name the control chart used in case of defects in statistical quality control. Answer: C-chart. Question 25. Write down control limits for x-charts when standards are given and not given. Answer: