💡 Chapter 14: Light – 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 convex mirror, magnifying glass, total internal reflection, refraction, optical fibre, and pencil bending phenomenon through multiple choice questions. Each MCQ is presented with the correct answer and detailed explanation as per the official PECTAA 2026 Physics curriculum.
📚 Related Resources – Chapter 14: Light
Light covers reflection, refraction, total internal reflection, optical fibres, lenses, prisms, dispersion, and optical instruments.
📖 Multiple Choice Questions & Answers (PECTAA 2026)
14.1 What type of image is always formed by a convex mirror?
✅ Correct Answer: B
Explanation: A convex mirror always forms an upright, virtual, and smaller image behind the mirror regardless of the object's distance.
Explanation: A convex mirror always forms an upright, virtual, and smaller image behind the mirror regardless of the object's distance.
14.2 The optical device which uses a convex lens to magnify an object by creating a virtual image:
✅ Correct Answer: C
Explanation: When an object is placed inside the focal length of a convex lens, it forms an erect, virtual, and magnified image on the same side. This defines the operation of a magnifying glass.
Explanation: When an object is placed inside the focal length of a convex lens, it forms an erect, virtual, and magnified image on the same side. This defines the operation of a magnifying glass.
14.3 Which statement best describes the phenomenon of total internal reflection?
✅ Correct Answer: B
Explanation: Total internal reflection occurs when light travelling from a denser to a rarer medium hits the boundary at an angle greater than the critical angle.
Explanation: Total internal reflection occurs when light travelling from a denser to a rarer medium hits the boundary at an angle greater than the critical angle.
14.4 A ray of light travelling from water to air bends:
✅ Correct Answer: B
Explanation: Light speeds up and bends away from the normal when it travels from an optically denser medium (water) into a rarer medium (air).
Explanation: Light speeds up and bends away from the normal when it travels from an optically denser medium (water) into a rarer medium (air).
14.5 The optical device which works on the principle of inverting an image for projection is:
✅ Correct Answer: C
Explanation: A slide projector places the slide between F and 2F of a convex lens to project a real, magnified, and inverted image onto a screen.
Explanation: A slide projector places the slide between F and 2F of a convex lens to project a real, magnified, and inverted image onto a screen.
14.6 What happens to light when it enters an optical fibre?
✅ Correct Answer: B
Explanation: Light stays trapped inside an optical fibre because it continuously strikes the core-cladding boundary at an angle greater than the critical angle.
Explanation: Light stays trapped inside an optical fibre because it continuously strikes the core-cladding boundary at an angle greater than the critical angle.
14.7 Which of the following phenomenon explains why a pencil appears bent when partially immersed in water?
✅ Correct Answer: C
Explanation: The pencil appears bent because light changes its speed and direction as it transitions from water into air.
Explanation: The pencil appears bent because light changes its speed and direction as it transitions from water into air.
📋 Answer Key Summary
| Q. No | Correct Answer | Explanation |
|---|---|---|
| 14.1 | (B) Virtual and diminished | A convex mirror always forms an upright, virtual, and smaller image behind the mirror regardless of the object's distance. |
| 14.2 | (C) Magnifying glass | When an object is placed inside the focal length of a convex lens, it forms an erect, virtual, and magnified image on the same side. This defines the operation of a magnifying glass. |
| 14.3 | (B) Light is completely reflected at the boundary of two media | Total internal reflection occurs when light travelling from a denser to a rarer medium hits the boundary at an angle greater than the critical angle. |
| 14.4 | (B) Away from the normal | Light speeds up and bends away from the normal when it travels from an optically denser medium (water) into a rarer medium (air). |
| 14.5 | (C) Slide projector | A slide projector places the slide between F and 2F of a convex lens to project a real, magnified, and inverted image onto a screen. |
| 14.6 | (B) It undergoes total internal reflection | Light stays trapped inside an optical fibre because it continuously strikes the core-cladding boundary at an angle greater than the critical angle. |
| 14.7 | (C) Refraction | The pencil appears bent because light changes its speed and direction as it transitions from water into air. |
📐 Key Formulas – Light
Refractive Index: \( n = \frac{c}{v} \)
Snell's Law: \( n_1 \sin i = n_2 \sin r \)
Critical Angle: \( C = \sin^{-1} \left( \frac{1}{n} \right) \)
Mirror / Lens Formula: \( \frac{1}{f} = \frac{1}{p} + \frac{1}{q} \)
Power of Lens: \( P = \frac{1}{f} \)
💡 Exam Tip:
For MCQs, read each option carefully. Pay attention to key concepts like image formation by mirrors, total internal reflection conditions, and refraction phenomena. These questions follow the PECTAA 2026 pattern and are prepared by Subject Specialist Muhammad Tayyab.
Unit 10Thermal Physics
Unit 11Transfer of Thermal Energy
Unit 12Waves
Unit 13Sound
Unit 14✨ Light
Unit 15Electrostatics
Unit 16Electricity
Unit 17Electromagnetism
Unit 18Electromagnetic Induction & EM Waves
Unit 19Electronics
Unit 20Atomic and Nuclear Physics
Unit 21Space and Environment
📖 Complete syllabus coverage for Class 10 Physics (PECTAA 2026) – Units 10 to 21
Created by Hira Science Academy | Aligned with PECTAA 2026 Syllabus