🌍 Chapter 21: Space & Environment – 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 chapter covers nuclear fusion, orbital distance, cyclones, global warming, Coriolis effect, rising sea levels, and background radiation. Each MCQ is presented with the correct answer 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 21
Space and Environment covers the Sun, nuclear fusion, orbital mechanics, cyclones, global warming, background radiation, and radiation safety.
📖 Multiple Choice Questions (PECTAA 2026)
21.1 What process generates energy in the Sun?
✅ Correct Answer: (B) Nuclear fusion
The Sun generates energy through nuclear fusion, where hydrogen atoms fuse together to form helium, releasing immense energy.
The Sun generates energy through nuclear fusion, where hydrogen atoms fuse together to form helium, releasing immense energy.
21.2 The factor which primarily determines a planet's surface temperature:
✅ Correct Answer: (B) its orbital distance from the Sun
A planet's distance from the Sun determines the amount of solar energy it receives, which primarily affects its surface temperature.
A planet's distance from the Sun determines the amount of solar energy it receives, which primarily affects its surface temperature.
21.3 What is the primary reason cyclones form over warm ocean waters?
✅ Correct Answer: (C) The rising of warm, moist air creating low pressure
Warm ocean waters heat the air above, causing it to rise and create a low-pressure area, which is the primary trigger for cyclone formation.
Warm ocean waters heat the air above, causing it to rise and create a low-pressure area, which is the primary trigger for cyclone formation.
21.4 Which of the following gas contributes the most to global warming?
✅ Correct Answer: (B) Carbon dioxide
Carbon dioxide is the major greenhouse gas released by human activities and contributes the most to global warming.
Carbon dioxide is the major greenhouse gas released by human activities and contributes the most to global warming.
21.5 How does the Coriolis effect influence cyclones?
✅ Correct Answer: (A) It causes cyclones to spin in opposite directions in different hemispheres
The Coriolis effect causes cyclones to spin anticlockwise in the northern hemisphere and clockwise in the southern hemisphere.
The Coriolis effect causes cyclones to spin anticlockwise in the northern hemisphere and clockwise in the southern hemisphere.
21.6 A major cause of rising sea levels is:
✅ Correct Answer: (C) melting glaciers and ice sheets
Global warming causes glaciers and ice sheets to melt, adding water to the oceans and raising sea levels.
Global warming causes glaciers and ice sheets to melt, adding water to the oceans and raising sea levels.
21.7 A significant source of background radiation is:
✅ Correct Answer: (B) cosmic rays from space
Cosmic rays from the Sun and other stars are a significant natural source of background radiation.
Cosmic rays from the Sun and other stars are a significant natural source of background radiation.
🌍 Key Concepts – Space & Environment
Nuclear Fusion: \(E = mc^2\)
Gravitational Force: \(F = G\frac{m_1m_2}{r^2}\)
Solar Energy and Distance: \(T \propto \frac{1}{r^2}\)
Unit 10Thermal Physics
Unit 11Transfer of Thermal Energy
Unit 12Waves
Unit 13Sound
Unit 14Light
Unit 15Electrostatics
Unit 16Electricity
Unit 17Electromagnetism
Unit 18Electromagnetic Induction & EM Waves
Unit 19Electronics
Unit 20Atomic and Nuclear Physics
Unit 21✨ Space and Environment
📖 Complete syllabus coverage for Class 10 Physics (PECTAA 2026) – Units 10 to 21
💡 Exam Tip:
For board exams, read each question carefully and eliminate obviously wrong options. These MCQs follow the PECTAA 2026 pattern and are prepared by Subject Specialist Muhammad Tayyab.
Created by Hira Science Academy | Aligned with PECTAA 2026 Syllabus