Test: Refraction Through a Lens - Class 10 MCQ

Light rays that pass through the first focus (F1) of a convex lens will emerge parallel to the principal axis after refraction. This property is useful in understanding the behavior of light in lens systems.

A convex lens can form both real and virtual images depending on the position of the object relative to the lens. A real image is formed when light rays actually converge, while a virtual image is formed when they appear to diverge.

The center of curvature is the center of the sphere from which the lens surface is a part. This concept is crucial in understanding how the lens impacts light refraction.

The power of a lens is defined as the reciprocal of its focal length, measured in diopters. This relationship helps in understanding how strongly the lens converges or diverges light.

The principal foci are points where light rays converge after passing through the lens. There are two foci (F1 and F2) located on either side of the lens, essential for understanding how lenses form images.

A convex lens has both surfaces bulging outward, which causes it to converge light rays to a point. This is in contrast to concave lenses, which curve inward and diverge light rays.

A concavo-convex lens has one surface that is convex and another that is concave, resulting in a lens that is thicker in the middle than at the edges. This unique shape affects how it refracts light.

A concave lens, also known as a diverging lens, causes incoming light rays to spread out or diverge. This is opposite to the behavior of convex lenses, which converge light rays.

A concave lens always produces a virtual image when the object is placed between the lens and its focal point. The rays appear to diverge from a point behind the lens, making it visible to the eye but not projectable on a screen.

The focal length of a convex lens is taken as positive because it converges light rays to a point on the opposite side of the lens, which is the convention used in optics.

The principal axis is defined as the horizontal line that connects the centers of curvature of both surfaces of the lens. It is crucial for understanding how light refracts through the lens.

A virtual image cannot be displayed on a screen because the light rays do not actually converge at a point; they only appear to diverge from a point. This property distinguishes virtual images from real images.

A concave lens is thicker at the edges than at the middle, which contributes to its ability to diverge light rays. This characteristic is essential for applications like eyeglasses for nearsightedness.

A real image is formed when light rays converge at a point, allowing it to be displayed on a screen. This is in contrast to virtual images, which cannot be projected.

A convex lens can produce a magnifying effect, particularly when used as a magnifying glass or simple microscope. By making objects appear larger, it highlights details that may not be visible to the naked eye.

The second rule indicates that a ray of light passing parallel to the principal axis will refract through the second focus (F2) of a convex lens. This rule is fundamental in constructing ray diagrams for lenses.

The optical centre is the point on the principal axis of the lens where light passes through without bending. This property is essential for the formation of images in lenses.

A magnifying glass is used to enlarge the appearance of an object, making it easier to see fine details. It works by bending light rays to create a virtual image that appears larger to the viewer's eye.

The power of a lens is measured in diopters (D), which represents the reciprocal of the focal length in meters. This unit helps quantify how strongly a lens can converge or diverge light.

A ray that passes through the optical center of a lens will emerge without deviation. This property is crucial for accurately tracing the path of light through the lens and understanding its optical effects.