📘 Chapter 6: Mechanical Properties of Matter – Multiple Choice Questions
Prepared by Muhammad Tayyab, Subject Specialist Physics, Govt Christian High School Daska. Based on PECTAA 2026 syllabus (National Curriculum 2023).
📖 What's Inside: This section covers multiple choice questions from Chapter 6 Mechanical Properties of Matter including Elasticity, Pressure, Hooke's Law, Pascal's Law, Barometer, and Hydraulic Systems. Each question includes an answer key and detailed explanation as per the official PECTAA 2026 Physics curriculum. Perfect for Punjab Boards (Lahore, Gujranwala, Multan, etc.) and all BISE boards across Pakistan.
📚 Related Resources – Chapter 6: Mechanical Properties of Matter
📋 Exercise Short Qs
📝 Short Qs
📖 Comprehensive Qs
🔢 Numerical Problems
✅ MCQs
✏️ Constructed Response
Mechanical Properties of Matter covers elasticity, pressure, Hooke's law, Pascal's law, and atmospheric pressure.
✅ Multiple Choice Questions & Answer Key (PECTAA 2026)
6.1 A wire is stretched by a weight \(w\). If the diameter of the wire is reduced to half of its previous value, the extension will become:
✅ Correct Answer: (D) four times
Extension \(\propto \frac{1}{A} \propto \frac{1}{d^2}\). If diameter is halved, area becomes \(1/4\), so extension becomes \(4\) times.
Extension \(\propto \frac{1}{A} \propto \frac{1}{d^2}\). If diameter is halved, area becomes \(1/4\), so extension becomes \(4\) times.
6.2 Four wires of the same material are stretched by the same load. Their dimensions are given below. Which of them will elongate most?
✅ Correct Answer: (D) Length \(4\,\text{m}\), diameter \(0.5\,\text{mm}\)
Extension \(\propto \frac{L}{A} \propto \frac{L}{d^2}\). For (D): \(\frac{4}{(0.5)^2} = 16\), which is largest.
Extension \(\propto \frac{L}{A} \propto \frac{L}{d^2}\). For (D): \(\frac{4}{(0.5)^2} = 16\), which is largest.
6.3 Two metal plates of area \(2\) and \(3\) square metres are placed in a liquid at the same depth. The ratio of pressures on the two plates is:
✅ Correct Answer: (A) \(1:1\)
Pressure depends only on depth and density, not on area. Same depth → same pressure.
Pressure depends only on depth and density, not on area. Same depth → same pressure.
6.4 The pressure at any point in a liquid is proportional to:
✅ Correct Answer: (D) all of the above
\(P = \rho gh\), so pressure depends on \(\rho\), \(g\), and \(h\) (depth).
\(P = \rho gh\), so pressure depends on \(\rho\), \(g\), and \(h\) (depth).
6.5 Pressure applied to an enclosed fluid is:
✅ Correct Answer: (C) transmitted unchanged to every portion of the fluid and walls of containing vessel
This is Pascal's law.
This is Pascal's law.
6.6 The principle of a hydraulic press is based on:
✅ Correct Answer: (B) Pascal's law
Hydraulic press works on Pascal's law of transmission of pressure.
Hydraulic press works on Pascal's law of transmission of pressure.
6.7 When a spring is compressed, what form of energy does it possess?
✅ Correct Answer: (B) Potential
A compressed spring stores elastic potential energy.
A compressed spring stores elastic potential energy.
6.8 What is the force exerted by the atmosphere on a rectangular block surface of length \(50\,\text{cm}\) and breadth \(40\,\text{cm}\)? The atmospheric pressure is \(100\,\text{kPa}\).
✅ Correct Answer: (A) \(20\,\text{kN}\)
\(F = P \times A\)
\(F = 100,000 \times (0.5 \times 0.4)\)
\(F = 100,000 \times 0.2 = 20,000\,\text{N} = 20\,\text{kN}\)
\(F = P \times A\)
\(F = 100,000 \times (0.5 \times 0.4)\)
\(F = 100,000 \times 0.2 = 20,000\,\text{N} = 20\,\text{kN}\)
📊 Answer Key Summary
6.1 D
6.2 D
6.3 A
6.4 D
6.5 C
6.6 B
6.7 B
6.8 A
📐 Key Concepts – Mechanical Properties of Matter (MCQs)
Hooke's Law: \(F = kx\)
Pressure: \(P = \frac{F}{A}\)
Liquid Pressure: \(P = \rho gh\)
Pascal's Law: Pressure transmitted equally
💡 Exam Tip:
For multiple choice questions, read each option carefully. Pay attention to key concepts like Hooke's law, pressure dependence on depth and density, Pascal's law, and energy forms. These questions follow the PECTAA 2026 pattern and are prepared by Subject Specialist Muhammad Tayyab.
Chapter 1Physical Quantities and Measurements
Chapter 2Kinematics
Chapter 3Dynamics
Chapter 4Turning Effect of Forces
Chapter 5Work and Energy
Chapter 6✨ Mechanical Properties of Matter
Chapter 7Thermal Properties of Matter
Chapter 8Magnetism
Chapter 9Nature of Science
📖 Complete syllabus coverage for Class 9 Physics (PECTAA 2026) – Chapters 1 to 9
Created by Hira Science Academy | Aligned with PECTAA 2026 Syllabus