PYQ Vault

Day 8: CBSE Class 10 Science

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

  1. Question 1

    Life Processes. Asked 3 times: 2023*, 2025*, 2026 (* = numbers or wording changed that year)

    14
    Give reasons for the following : (a) Plants do not have an excretory system so how they excrete their wastes ? (b) Why do mammals and birds have double circulation ?

  2. Question 2

    Life Processes. Asked 3 times: 2024*, 2025*, 2026 (* = numbers or wording changed that year)

    14
    Give reasons for the following : (a) Herbivores have a longer small intestine. (b) Inner lining of small intestine has numerous finger-like projections. (c) Rate of breathing in aquatic organisms is much faster than that in terrestrial organisms.

  3. Question 3

    Life Processes. Asked 3 times: 2023*, 2025*, 2026 (* = numbers or wording changed that year)

    13
    Complete the pathways given below, showing the breakdown of glucose. Glucose →‘A’\xrightarrow{\text{‘A’}} Pyruvate + Energy Pyruvate →in yeast\xrightarrow{\text{in yeast}} ‘B’ + ‘C’ + Energy Pyruvate →in muscle cells\xrightarrow{\text{in muscle cells}} ‘D’ + Energy Pyruvate →in mitochondria\xrightarrow{\text{in mitochondria}} ‘E’ + ‘F’ + Energy Identify ‘A’, ‘B’, ‘C’, ‘D’, ‘E’ and ‘F’.

  4. Question 4

    Light — Reflection and Refraction. Asked 3 times: 2024*, 2025*, 2026 (* = numbers or wording changed that year)

    33
    Draw the ray diagram showing refraction through a glass slab and write the relation between angle of incidence, angle of refraction and refractive index of glass.

  5. Question 5 (case study, 4 parts)

    Light — Reflection and Refraction. Asked 3 times: 2024*, 2025*, 2026 (* = numbers or wording changed that year)

    The variation of image distance (v)(v) with the object distance (u)(u) for a convex lens is given in the following observation table. Analyse it and answer the questions given below :
    S.No.Object distance (u)(u) cmImage distance (v)(v) cm
    1−150-150+30+30
    2−75-75+37⋅5+37{\cdot}5
    3−50-50+50+50
    4−37⋅5-37{\cdot}5+75+75
    5−30-30+150+150
    6−15-15+37⋅5+37{\cdot}5
    38 (a)
    Without calculation, find out the focal length of the given convex lens. Justify your answer.
    38 (b)
    Which one of the observations given in the table is not correct and why ?
    38 (c) (i)
    Find out the value of magnification for u=−30u = -30 cm. Write the nature of the image formed. Give reason for your answer.
    38 (c) (ii)
    Analyse the data given in the table above and draw the labelled ray diagram for u=−30u = -30 cm and v=150v = 150 cm.