ROUTERA

Light-Reflection and Refraction

Class 10th Science Chapter Case Study

Case Study 1: Reflection of Light

Case Description:
A concave mirror is used in a dental clinic to magnify the teeth for better inspection. When a dentist looks into the mirror, the image of the patient's teeth appears larger than the actual size. This phenomenon occurs due to the reflection of light from the concave surface of the mirror.

MCQs:

  1. What type of mirror is used in dental clinics for magnifying images?

    • A) Plane mirror
    • B) Convex mirror
    • C) Concave mirror
    • D) Spherical mirror

  2. What is the nature of the image formed by a concave mirror when the object is placed between the focus and the mirror?

    • A) Real and inverted
    • B) Virtual and upright
    • C) Diminished
    • D) Same size

  3. Which of the following is true about the focal point of a concave mirror?

    • A) It is located behind the mirror.
    • B) It is the point where parallel rays converge.
    • C) It is the center of curvature.
    • D) It is always at infinity.

  4. When parallel rays of light strike a concave mirror, they converge at the focal point. What is this property of mirrors called?

    • A) Reflection
    • B) Refraction
    • C) Dispersion
    • D) Absorption

Case Study 2: Refraction of Light

Case Description:
A glass prism is used to disperse white light into its constituent colors. When a beam of white light enters the prism, it bends at the boundaries, separating into colors: red, orange, yellow, green, blue, indigo, and violet (VIBGYOR). This phenomenon illustrates the refraction of light.

MCQs:

  1. What is the phenomenon of light bending as it passes from one medium to another called?

    • A) Reflection
    • B) Dispersion
    • C) Refraction
    • D) Absorption

  2. When light enters a denser medium like glass from air, how does it behave?

    • A) It speeds up and bends away from the normal.
    • B) It slows down and bends towards the normal.
    • C) It remains unchanged.
    • D) It gets absorbed.

  3. What are the primary colors of light that can be seen when white light passes through a prism?

    • A) Red, green, blue
    • B) Yellow, cyan, magenta
    • C) VIBGYOR
    • D) Black, white, gray

  4. Which color of light is refracted the least when passing through a prism?

    • A) Violet
    • B) Blue
    • C) Yellow
    • D) Red

Case Study 3: Total Internal Reflection

Case Description:
Optical fibers use the principle of total internal reflection to transmit light signals over long distances. When light travels through the fiber at an angle greater than the critical angle, it reflects entirely within the fiber without any loss of signal.

MCQs:

  1. What is total internal reflection?

    • A) When light reflects off a smooth surface
    • B) When light passes through a medium without bending
    • C) When light reflects entirely within a medium at angles greater than the critical angle
    • D) When light is absorbed by a medium

  2. Which of the following is a necessary condition for total internal reflection to occur?

    • A) Light must enter a denser medium.
    • B) Light must enter a less dense medium.
    • C) Light must strike the boundary at any angle.
    • D) Light must have a wavelength shorter than the critical angle.

  3. What determines the critical angle for a given pair of media?

    • A) The thickness of the medium
    • B) The refractive indices of the media
    • C) The temperature of the media
    • D) The wavelength of the light

  4. In which of the following applications is total internal reflection commonly used?

    • A) Lenses
    • B) Mirrors
    • C) Optical fibers
    • D) Magnifying glasses

Case Study 4: Lenses and Image Formation

Case Description:
A convex lens is placed in front of a light source, projecting an image onto a screen. When the object is moved closer to the lens, the image size changes, demonstrating the lens's ability to focus light. This property is utilized in cameras and projectors.

MCQs:

  1. What type of lens is used to converge light rays to form an image?

    • A) Concave lens
    • B) Convex lens
    • C) Plane lens
    • D) Cylindrical lens

  2. What happens to the image produced by a convex lens as the object moves closer to it?

    • A) The image becomes smaller.
    • B) The image becomes larger and inverted.
    • C) The image disappears.
    • D) The image remains the same size.

  3. Which of the following describes a real image formed by a convex lens?

    • A) Upright and virtual
    • B) Inverted and can be projected on a screen
    • C) Diminished and upright
    • D) None of the above

  4. If an object is placed at a distance greater than the focal length but less than twice the focal length from a convex lens, the image will be:

    • A) Real and diminished
    • B) Virtual and upright
    • C) Real and larger than the object
    • D) Real and inverted

Case Study 5: The Human Eye and Vision

Case Description:
The human eye functions like a camera, using a convex lens to focus light on the retina. The eye can adjust its focal length by changing the shape of the lens using ciliary muscles, allowing us to see objects at varying distances clearly. Common vision problems include myopia (nearsightedness) and hyperopia (farsightedness).

MCQs:

  1. What type of lens is present in the human eye?

    • A) Concave lens
    • B) Convex lens
    • C) Cylindrical lens
    • D) Bifocal lens

  2. Which part of the eye is responsible for focusing light onto the retina?

    • A) Cornea
    • B) Iris
    • C) Lens
    • D) Pupil

  3. What is myopia?

    • A) Difficulty seeing distant objects
    • B) Difficulty seeing near objects
    • C) Normal vision
    • D) Inability to perceive colors

  4. How can myopia be corrected?

    • A) Using a convex lens
    • B) Using a concave lens
    • C) Using bifocal lenses
    • D) Using tinted lenses