PYQ Vault

Day 128: CBSE Class 10 Science

5 questions (8 parts). Try each one first, then open its answer.

  1. Question 1

    Light — Reflection and Refraction. Asked once: 2025 (same type asked 3 times)

    31
    A convex lens forms an 8⋅08{\cdot}0 cm long image of a 2⋅02{\cdot}0 cm long object which is kept at a distance of 6⋅06{\cdot}0 cm from the optical centre of the lens. If the object and the image are on the same side of the lens, find (i) the nature of the image, (ii) the position of the image, and (iii) the focal length of the lens.

  2. Question 2

    Light — Reflection and Refraction. Asked once: 2024 (same type asked 3 times)

    31 (b)
    (i) The image of an object formed by a mirror is real, inverted and is of magnification-1. If the image is at a distance of 30 cm from the mirror, where is the object placed ? Give reason to justify your answer. (ii) Where would the image be if the object is moved 15 cm towards the mirror ? Draw ray diagram for the new position of the object to justify your answer.

  3. Question 3

    Light — Reflection and Refraction. Asked once: 2025 (same type asked 3 times)

    36 (b)
    (i) A student wishes to study the image formation by a concave mirror using candle flame as object. State the type of the image formed by the mirror and mention the change in the image formed, if any, that he observes when the candle flame is gradually moved away from the pole of the mirror. Draw a ray diagram to show the image formation when the object distance is nearly equal to the radius of curvature of the mirror. (ii) A convex mirror used for rear-view on an automobile has a focal length of 3⋅03{\cdot}0 m. If a bus is located at 6⋅06{\cdot}0 m from this mirror, use mirror formula to find the position of the image of the bus as seen in the mirror.

  4. Question 4

    Light — Reflection and Refraction. Asked once: 2026 (same type asked 3 times)

    33
    With the help of the given ray diagram, calculate the refractive index of Medium 2 with respect to Medium 1. (Given that 3=1⋅732\sqrt{3} = 1{\cdot}732)

  5. Question 5 (case study, 4 parts)

    Light — Reflection and Refraction. Asked once: 2024 (same type asked 3 times)

    A highly polished surface such as a mirror reflects most of the light falling on it. In our daily life we use two types of mirrors — plane and spherical. The reflecting surface of a spherical mirrors may be curved inwards or outwards. In concave mirrors, reflection takes place from the inner surface, while in convex mirrors reflection takes place from the outer surface.
    39 (a)
    Define the principal axis of a concave mirror.
    39 (b)
    A ray of light is incident on a concave mirror, parallel to its principal axis. If this ray after reflection from the mirror passes through the principal axis from a point at a distance of 10 cm from the pole of the mirror, find the radius of curvature of the mirror.
    39 (c) (i)
    An object is placed at a distance of 10 cm from the pole of a convex mirror of focal length 15 cm. Find the position of the image.
    39 (c) (ii)
    A mirror forms a virtual, erect and diminished image of an object. Identify the type of this mirror. Draw a ray diagram to show the image formation in this case.