Download Class 9 Physics Chapter 6 Exercise Constructive Questions PDF both English and Urdu medium for quick revision and exam preparation. This PDF is helpful for 9th class students who want to prepare important exercise comprehensive questions according to the new syllabus. Students can use it to revise chapter-wise questions, improve their concepts, and prepare better for school tests and board exams.
Chapter 6 Constructive Questions: Mechanical Properties of Matter
The constructive questions at the end of Chapter 6 describe a situation and ask you to account for it. They are the closest thing in the textbook to the nine-mark questions in the annual paper. In this chapter they deal with:
- Why a sharp knife cuts more easily than a blunt one.
- How a hydraulic press multiplies force.
- Why a steel ship floats while a steel nail sinks.
- What happens to a spring stretched past its elastic limit, and what the stress-strain graph shows.
What a Full-Mark Answer Looks Like Here
These answers are marked point by point, so an answer that circles the idea without stating it plainly scores badly. For Mechanical Properties of Matter in particular:
- Argue from the formula: pressure equals force divided by area, so a smaller area gives a larger pressure.
- For floating, compare the weight of the body with the weight of fluid displaced.
- Name the law or principle first, then apply it to the objects actually named in the question.
- Draw and label a diagram wherever one is possible, since it often carries a mark by itself.
Why This Set Repays the Effort
Most students drill the short questions and leave the constructive ones until last, which is the wrong way round. Eighteen of the sixty marks in the annual paper come from long questions built on exactly this material, and a reasoning question cannot be answered from memory alone. Attempt them in writing with the book closed, then compare.
Frequently Asked Questions
Why does a steel ship float when a steel nail sinks?
Because the ship is hollow, so its average density is less than that of water and it displaces a weight of water equal to its own. The solid nail is denser than water throughout.
How many marks do the long questions carry?
Eighteen of the sixty. Three are offered and you attempt any two, at nine marks each, split into a four-mark and a five-mark part.
Related Class 9 Physics Resources
For the two-mark recall answers from the same chapter see the Chapter 6 exercise short questions, and check your understanding with the Chapter 6 online test. Continue with Chapter 5 and Chapter 7, or download the 25 Class 9 Physics guess papers for timed practice. Browse Class 9 Physics notes for the rest.