Important Questions Test: Light - Class 7 MCQ

Moon does not have any light of its own; it reflects the light of the sun.

Smooth surfaces reflect light, and rough surfaces do not.Therefore surfaces cannot produce clear images.

Silver is shiny and is a good reflector. It reflects about 90 percent of light falling on it. That is why, it is used for making high reflecting mirrors. one surface of the mirror is silvered because it helps the light rays to reflect.

• When light falls on a shiny surface, it doesn't get absorbed or disappear.
• Instead, it changes direction. Imagine light as a bouncy ball hitting a shiny wall – it bounces off in another direction.
• This bouncing of light off shiny surfaces helps us see reflections and images around us. So, when light meets something shiny, it doesn't go through or vanish; it reflects and changes its path!

Light travels along a straight line means light moves in a direct path without bending or curving. Just like drawing a straight line from one point to another without any curves or turns.

• In the world around us, light can sometimes change its path when it falls on shiny objects. Imagine light like a bouncing ball.
• When light hits a shiny surface, it can bounce off in a different direction, just like how a ball bounces off a wall.
• This change in direction is called reflection of light.
• So, when light falls on a shiny surface, it can indeed change its path, making the statement True.

- When you see your image in a mirror, it appears exactly like you.
- However, the image is reversed left to right, known as lateral inversion.
- The size and proportions of the image match your real appearance.
- Mirrors reflect light, creating a virtual image that appears behind the mirror surface.
- The image will look the same in terms of height and width, assuming a flat mirror.
- Therefore, your image is exactly like you in size and appearance, just laterally inverted.

The image in a plane mirror is erect, which means it is the same way up as the object you see in the mirror.

• When Boojho saw his image in a plane mirror, the image he saw was actually of the same size as him. In a plane mirror, the size of the image is the same as the size of the object.
• So, the statement is False.
• The mirror shows exactly the same size of the object, not smaller or larger.

• Convex surfaces are outwardly curved, like the outer surface of a bell. When light reflects off a convex surface, it diverges, and any image formed will be virtual, smaller, and upright. This is likely the type of surface where Boojho saw his reflection.

• Flat surfaces produce images that are the same size as the object, which is unlikely in the case of a bell.

• Concave surfaces are inwardly curved and can produce magnified images depending on the position of the object relative to the surface, which doesn't fit the description for a bell's outer surface.

• Rough surfaces generally scatter light in many directions and do not form a clear image.

Therefore, the correct answer is Convex.

Concave mirrors are used by the doctors for examining eyes, ears, nose and throat. Concave mirrors are used to obtain an enlarged image of these organs.

• Yes, light can pass through both convex and concave lenses.
• Convex lenses are thicker in the middle and thinner at the edges, like a magnifying glass, while concave lenses are thinner in the middle and thicker at the edges.
• Convex lenses can converge light rays, bringing them together, while concave lenses diverge light rays, spreading them apart.
• So, it is True that light can pass through both convex and concave lenses, helping us see things differently!

• When you hold a convex lens in the path of sunrays and adjust the distance until you see a bright spot on the paper, the paper begins to burn.
• This happens because the convex lens concentrates the sunlight on the paper, making it hot enough to start burning.
• It's important to remember to be very careful when working with lenses and sunlight as they can get very hot and cause burns.

A convex lens is a type of lens that bends light inwards, bringing it together at a focal point. This lens is called a converging lens because it makes light rays converge or come together at a point. When light passes through a convex lens, it focuses the light to create an image.

• When light goes through a curved glass (like a magnifying glass), it bends inwards.
• This is what we call a converging lens, just like how a convex lens works.
• So, the statement is True!