# Class 10 Physics Chapter 3 (12) Important Short Questions 2024

Students if you are looking for the Class 10 Physics Chapter 3 (12) Important Short Questions Notes if yes? then you visit the right place where you can easily find chapter 3 most important short questions only without answers but it is your responsibility to find answers from your 10th class Physics book.

Students You know that these Chapter 3 GEOMETRICAL OPTICS Questions of Physics are helpful so don’t ignore to find answers from your physics of class 10

## Class 10 Physics Chapter 12 Important Short Questions

• When light traveling in a certain medium falls on the surface of another medium, a part of it turns back in the same medium. This is called the reflection of light. There are two laws of reflection:
• i. The incident ray, the reflected ray, and the normal all lie in the same plane.
• ii. The angle of incidence is equal to the angle of reflection (i.e., i = r).
• Like plane surfaces, spherical surfaces also reflect light satisfying the two laws of reflection.
• In mirrors, image formation takes place through reflection of light while in lenses image is formed through refraction of light.
• The equation relating the distance of the object p from the mirror/lens, the distance of the image q, and the focal length f of the mirror/lens is called the mirror/lens formula, given by
• The magnification of a spherical mirror or thin lens is defined as “the ratio of the image height to the object height.” i.e.,
• The power of a lens is defined as “the reciprocal of its focal length in meters”. Thus Power of a lens = P = 1 / focal length in meters. The SI unit of power of a lens is “Dioptre”, denoted by a symbol D. If is expressed in meters so that 1 D = 1 m. Thus, 1 Dioptre f is the power of a lens whose focal length is 1 meter.
• The refractive index ‘n’ of a material is the ratio of the speed of light ‘c’ in air to the speed of light ‘v’ in the material, thus
• The bending of light from its straight path as it passes from one medium into another is called refraction.
• Refraction of light takes place under two laws called laws of refraction. These are stated as:
• i. The incident ray, the refracted ray, and the normal at the point of incidence all lie in the same plane.
• The angle of incidence for which the angle of refraction becomes 90 is called critical
• angle. When the angle of incidence becomes larger than the critical angle, no
• refraction occurs. The entire light is reflected back into the denser medium. This is known as the total internal reflection of light.
• A simple microscope, also known as a magnifying glass, is a convex lens that is used to produce magnified images of small objects.
• A compound microscope is used to investigate the structure of small objects and has two converging lenses, the objective, and the eyepiece.
• A telescope is an optical instrument that is used to observe distant objects using lenses or mirrors. A telescope that uses two converging lenses is called a refracting telescope. A telescope in which the objective lens is replaced by a concave mirror is called reflecting power telescope.
• The magnifying power is defined as “the ratio of the angle subtended by the image as seen through the optical device to that subtended by the object at the unaided eye”.
• The resolving power of an instrument is its ability to distinguish between two closely placed objects.
• The ability of the eye to change the focal length of its lens so as to form a clear image of an object on its retina is called its power of accommodation.
• The disability of the eye to form distinct images of distant objects on its retina is known as nearsightedness. The nearsighted eye can be corrected with glass or contact lenses that use diverging lenses Light rays from distant objects will. diverge by this lens before entering the eye.
• The disability of the eye to form distinct images of nearby objects on its retina is known as farsightedness. These defects can be corrected with the aid of a suitable converging lens. The lens refracts the light rays more towards the principal axis before they enter the eye.

### REVIEW QUESTIONS

• What do you understand by the reflection of light? Draw a diagram to illustrate reflection at a plane surface.
• Describe the following terms used in reflection:
• (i) normal
• (ii) angle of incidence
• (iii) angle of reflection
• State laws of reflection. Describe how they can be verified graphically.
• Define refraction of light. Describe the passage of light through parallel-sided transparent material.
• Define the following terms used in refraction:
• (i) angle of incidence
• (ii) angle of refraction
• What is meant by the refractive index of a material? How would you determine the refractive index of a rectangular glass slab?
• State the laws of refraction of light and show how they may be verified using rectangular glass slabs and pins.
• What is meant by the term total internal reflection?
• State the conditions for total internal reflection.
• What is the critical angle? Derive a relationship between the critical angle and the refractive index of a substance.
• What are optical fibers? Describe how total internal reflection is used in light propagating through optical fibers.
• Define the following terms applied to a lens:
• (i) principal axis
• (ii) optical center
• (iii) focal length
• What is meant by the principal focus of a (a) convex lens (b) concave lens? Illustrate your answer with ray diagrams.
• Describe how light is refracted through a convex lens.
• With the help of a ray diagram, you can show the use of a thin converging lens as a magnifying glass.
• Describe how light is refracted through a convex lens.
• A coin is placed at a focal point of a converging lens. Is an image formed? What is its nature?
• What are the differences between real and virtual images?
• How does a converging lens form a virtual image of a real object? How does a diverging lens can form a real image of a real object?
• Define the power of a lens and its units.
• Describe the passage of light through a glass prism and measure the angle of deviation.
• Define the terms resolving power and magnifying power.
• Draw the ray diagrams of
• (i) simple microscope
• (ii) compound microscope
• (iii) refracting telescope
• Mention the magnifying powers of the following optical instruments:
• (i) simple microscope
• (ii) compound microscope
• (iii) refracting telescope
• Draw ray diagrams to show the formation of images in the normal human eye.
• What is meant by the terms nearsightedness and farsightedness? How can these defects be corrected?

### Conclusion

The topic of this post is 10th Class Physics Chapter 3 GEOMETRICAL OPTICS Short Questions without a PDF file. We add this post to the 10th Class Physics Notes category where students can easily find the Chapter 3 Short Questions type study solutions and much more that students need to be related to the Class 10 Physics Book.