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Q1. The image formed by a convex mirror is always:
A convex mirror always forms a virtual, erect, and diminished (smaller) image regardless of the object’s position. It is a diverging mirror and cannot form real images. This property makes it useful as a rear-view mirror.

Q2. Why are convex mirrors used as side view mirrors (rear view mirrors) in vehicles?
Convex mirrors provide a wider field of view, allowing drivers to see a larger area behind them. The images are smaller and upright, which helps in judging traffic. This is why they are used as side view mirrors.

Q3. A convex mirror forms a virtual image. This means that the image:
A virtual image is formed when light rays appear to diverge from a point behind the mirror. They do not actually meet, so the image cannot be captured on a screen. Virtual images are always erect (upright).

Q4. The image of a car behind you in a convex side view mirror appears smaller than the actual car. This is because:
A convex mirror diverges light rays, causing the reflected rays to spread out. This makes the image smaller (diminished) than the actual object. The material, absorption, or dirtiness of the mirror are not the reasons.

Q5. A convex lens is also called a converging lens because:
A convex lens converges parallel rays of light to a single point called the focus. This is why it is called a converging lens. It is thicker in the middle and thinner at the edges.

Q6. A concave lens is also called a diverging lens because:
A concave lens diverges (spreads out) light rays. It is thinner in the middle and thicker at the edges. This is why it is called a diverging lens. It cannot form real images.

Q7. The image formed by a convex lens when the object is placed beyond the focus is:
When an object is placed beyond the focus of a convex lens, the image formed is real and inverted. It can be captured on a screen. The size of the image depends on the exact position of the object.

Q8. The image formed by a convex lens when the object is placed between the lens and its focus is:
When an object is placed between the lens and its focus, a convex lens forms a virtual, erect, and magnified image. This is the principle behind a magnifying glass. The image cannot be captured on a screen.

Q9. A magnifying glass is made of:
A magnifying glass is made of a convex lens. When an object is placed between the lens and its focus, the convex lens forms a virtual, erect, and magnified image, making small objects appear larger.

Q10. To use a convex lens as a magnifying glass, where should you place the object?
To use a convex lens as a magnifying glass, the object must be placed between the lens and its focus. This produces a virtual, erect, and magnified image. If the object is beyond the focus, the image is real and inverted.

Q11. When a convex lens is used to form a real image of the Sun on a piece of paper, what happens?
A convex lens focuses parallel rays of sunlight to a point (the focus). This concentrates the Sun’s energy, which can generate enough heat to burn paper. This is a demonstration of the converging power of a convex lens.

Q12. Sunlight appears white to us, but it is actually:
Sunlight (white light) is actually composed of seven colours: violet, indigo, blue, green, yellow, orange, and red (VIBGYOR). It appears white because our eyes blend these colours together. A prism can separate them.

Q13. A rainbow is produced when:
A rainbow forms when sunlight enters water droplets in the air, is refracted and dispersed into colours, and then reflected inside the droplet before exiting. This separates the light into the seven colours of the spectrum.

Q14. You can see a rainbow only when your back is towards the Sun. This is because:
To see a rainbow, the Sun must be behind you and rain must be in front of you. The sunlight passes through the raindrops and is refracted, dispersed, and reflected back towards you. If the Sun is in front, the rainbow would be behind you.

Q15. A glass prism splits white light into seven colours. This phenomenon is called:
The splitting of white light into its constituent colours is called dispersion. This happens because different colours bend by different amounts when passing through a prism. Violet bends the most, and red bends the least.

Q16. The seven colours of white light in order (from top to bottom in a rainbow or prism spectrum) are:
The seven colours of white light in order from top to bottom (or from the most bent to the least bent) are Violet, Indigo, Blue, Green, Yellow, Orange, and Red. The acronym VIBGYOR is commonly used to remember this order. Red is the least bent, and violet is the most bent.

Q17. A rear view mirror in a car is usually a:
The central rear-view mirror inside a car is usually a plane mirror, but the side view mirrors are convex. However, the question generally refers to side mirrors. Convex mirrors are used because they give a wider field of view.

Q18. The warning “Objects in the mirror are closer than they appear” is found on:
This warning is printed on convex side-view mirrors. Because convex mirrors make objects appear smaller, they also make them appear farther away than they actually are. This warning reminds drivers that objects are closer than they appear in the mirror.

Q19. A prism is a transparent optical element with:
A prism is a transparent optical element with flat, polished surfaces that refract light. It has at least two non-parallel surfaces that cause the light to bend and disperse. The most common prism is triangular in shape.

Q20. When white light passes through a prism, which colour bends the most?
Violet light bends the most when passing through a prism because it has the shortest wavelength and travels slower in glass than other colours. Red light bends the least because it has the longest wavelength and travels fastest in glass.

Q21. When white light passes through a prism, which colour bends the least?
Red light bends the least when passing through a prism. It has the longest wavelength among the visible colours and travels fastest in glass, so it is deviated the least. Violet bends the most.

Q22. A convex mirror is used as a side view mirror because it:
Convex mirrors have a wider field of view, allowing drivers to see a larger area behind them. This is the primary reason they are used as side-view mirrors. They do not magnify images or form real images.

Q23. The image formed by a concave lens is always:
A concave lens always forms a virtual, erect, and diminished image, regardless of the object’s position. It is a diverging lens, so it cannot form real images. The image is smaller than the object.

Q24. Which of the following statements about a real image formed by a convex lens is correct?
A real image can be captured on a screen because the light rays actually converge to form the image. Real images formed by convex lenses are always inverted, and their size depends on the object’s position. They are formed when the object is beyond the focus.

Q25. Which of the following statements about a virtual image formed by a convex lens is correct?
A convex lens forms a virtual, erect, and magnified image when the object is placed between the lens and its focus. This is the principle of a magnifying glass. Virtual images cannot be captured on screens and are always erect.

Q26. You see a rainbow in the sky after a rain shower. The Sun is most likely:
To see a rainbow, the Sun must be behind you. The light from the Sun passes through the raindrops in front of you and is reflected back towards you. This is why you see the rainbow in front of you with the Sun at your back.

Q27. What happens when you try to capture a virtual image formed by a convex mirror on a screen?
A virtual image cannot be captured on a screen because the light rays do not actually meet at the image point. They only appear to diverge from that point. Therefore, no image will appear on the screen.

Q28. A convex lens is used in a camera to:
A camera uses a convex lens to form a real, inverted, and diminished image of the object on the film or sensor. This is because the object is placed beyond the focus of the lens. The image is real because it is formed on the film.

Q29. A concave mirror and a convex lens both can:
Both concave mirrors and convex lenses can form both real and virtual images depending on the object’s position. When the object is beyond the focus, they form real images. When the object is between the pole/focus, they form virtual images.

Q30. The image formed by a convex mirror is always diminished. This means the image is:
“Diminished” means the image is smaller than the object. A convex mirror always forms a diminished image, which is why objects appear smaller in convex mirrors. This is a characteristic of convex mirrors.

Q31. A ray of light passes through a glass prism. Which of the following happens?
When light passes through a prism, it bends at both surfaces (entry and exit) and is dispersed into its constituent colours. The bending and dispersion occur because different colours have different speeds in glass.

Q32. Why does a convex lens focus sunlight to a point?
A convex lens refracts parallel rays of light and bends them so they meet at a single point called the focus. This is why it is called a converging lens. This property is used to focus sunlight and can even burn paper.

Q33. A student looks at a distant tree through a convex lens. The image of the tree will be:
When a distant object is viewed through a convex lens, the image formed is real, inverted, and diminished (smaller). This is the same principle used in cameras, where distant objects form smaller images on the film.

Q34. The reason a convex mirror is preferred as a side view mirror over a plane mirror is:
Convex mirrors provide a wider field of view, allowing drivers to see a larger area behind them. This is more important than the distortion in size, which is why convex mirrors are preferred as side-view mirrors in vehicles.

Q35. A convex lens forms a real, inverted, and same-sized image of an object. Where is the object placed?
When an object is placed at twice the focal length (2F) of a convex lens, the image formed is real, inverted, and the same size as the object. This is a special case in lens imaging. At the focus, the image is at infinity; between focus and 2F, the image is magnified.

Q36. Which of the following devices uses a convex lens to form a magnified, virtual image?
A magnifying glass uses a convex lens to form a virtual, erect, and magnified image when the object is placed between the lens and its focus. Cameras and projectors form real images, and the human eye uses a lens to form real images on the retina.

Q37. When white light passes through a prism, the band of colours obtained is called a:
The band of colours obtained when white light passes through a prism is called a spectrum. The spectrum consists of seven colours: violet, indigo, blue, green, yellow, orange, and red (VIBGYOR). A rainbow is a natural spectrum formed by water droplets.

Q38. A convex lens is used to correct which vision defect?
A convex lens is used to correct farsightedness (hypermetropia). In hypermetropia, the image is formed behind the retina because the eye cannot focus on near objects. A convex lens converges the light before it enters the eye, helping to form the image on the retina.

Q39. A concave lens is used to correct which vision defect?
A concave lens is used to correct nearsightedness (myopia). In myopia, the image is formed in front of the retina because the eye focuses light too strongly. A concave lens diverges the light before it enters the eye, moving the image back onto the retina.

Q40. You are given a convex lens and a white screen. How can you determine the approximate focal length of the lens?
The focal length of a convex lens can be determined by focusing the image of a distant object on a screen. The distance between the lens and the screen where the image is sharp is approximately the focal length. This is because parallel rays from a distant object converge at the focus.

Q41. Why does a rainbow appear in the shape of an arc (a curve) rather than a straight line?
A rainbow is circular because it is formed by raindrops that make a specific angle (about 42°) between the Sun, the raindrop, and the observer’s eye. This angle creates a cone of light, and the arc we see is the intersection of that cone with the sky. The Earth blocks the lower part, making it an arc.

Q42. A convex mirror is used in supermarkets and shops as a security mirror because:
Convex mirrors are used as security mirrors because they provide a wide field of view, allowing staff to monitor a large area. They show a smaller but wider view, which is useful for surveillance. They do not form real images or magnify images.

Q43. Which of the following correctly describes the image formed by a convex lens when the object is at the focus (F)?
When an object is placed exactly at the focus of a convex lens, the refracted rays emerge parallel to each other. They do not converge or diverge, so no real or virtual image is formed at a finite distance. The image is said to be formed at infinity.

Q44. The inside of a spoon acts as a concave mirror. The outside of a spoon acts as a convex mirror. If you look at your face in the outside of a spoon, your image will be:
The outside of a spoon acts as a convex mirror. A convex mirror always forms a virtual, erect (upright), and diminished (smaller) image. So your image will be upright and smaller.

Q45. A student observes that a convex lens forms a real, inverted image of a candle on a screen. If he covers the top half of the lens with black paper, what will happen to the image?
If half the lens is covered, the complete image still forms, but it becomes dimmer because less light passes through the lens. Each part of the lens contributes to the entire image. The image does not disappear or change in orientation.

Q46. Which of the following is NOT a use of a convex lens?
Correcting nearsightedness (myopia) requires a concave lens, not a convex lens. Convex lenses are used in magnifying glasses, cameras, telescopes, and for correcting farsightedness (hypermetropia). A concave lens diverges light, which is needed to correct myopia.

Q47. A prism splits white light into colours. If you place another identical prism upside down in the path of this coloured light, what will happen?
If a second prism is placed upside down in the path of the dispersed light, the colours will recombine to form white light again. This is because the second prism reverses the dispersion effect, bending the colours back together. This experiment demonstrates that white light is a mixture of colours.

Q48. A driver is reversing a car using only the side view mirrors (which are convex). Why might the driver misjudge the distance to an object behind the car?
Convex mirrors diminish the image, making objects appear smaller than they really are. This can make them appear farther away than they actually are, leading to misjudgment of distance. This is why the warning “Objects in mirror are closer than they appear” is printed on them.

Q49. Which of the following statements about the image formed by a convex lens is correct when the object is placed beyond 2F (twice the focal length)?
When an object is placed beyond 2F of a convex lens, the image is real, inverted, and diminished (smaller than the object). This is the principle used in cameras to capture distant objects. Between F and 2F, the image is magnified.

Q50. You are standing with your back to the Sun and see a beautiful rainbow in front of you. Which of the following is true about the position of the rain?
To see a rainbow, the Sun must be behind you and the rain must be in front of you. The sunlight passes through the raindrops in front of you, is refracted, dispersed, and reflected back towards you, forming the rainbow. If the rain were behind you or overhead, you would not see the rainbow in front of you.