Guide on Quality Control: Based on PMBOK Guide Seventh Edition

Understanding Quality Control:
Quality control is a process utilized in project management that focuses on maintaining the quality of an organization's deliverables. It involves various activities like inspection, testing, and corrections that ensure the product or service meets the required standards.

Importance:
Quality control is crucial as it helps maintain a steady quality level and reduces waste. Often, it aids in fostering customer satisfaction and trust.

Quality Control Mechanism:
Quality control works by setting particular quality standards based on a customers' needs and implementing strategies to ensure these standards are met. Quality control may use statistical techniques and other methods to manage quality.

Exam Tips:
Understanding the clear differences between quality assurance and quality control aids in correctly answering the related questions. Quality Assurance is a proactive process, while Quality Control is a reactive one. Remember, 'control' in quality control implies measurement and monitoring. Use this concept to identify the correct answers.
Quality assurance concerns with process management, ensuring things are done correctly right from the beginning, while quality control concerns with the end product, making sure that it's as per the defined standards.

For answering scenario-based questions, follow the Plan-Do-Check-Act(PDCA) approach. When given a problem, determine where the issue occurred in the PDCA cycle. To answer the 'What should the project manager do next?' questions, apply the PDCA rule: If you've planned and done, then check. If you've checked and acted, then plan.

In conclusion, understanding the Quality Control concept, its applications, and practical approach extensively will help you answer the examination questions successfully.