PYQ Vault

Day 75: CBSE Class 10 Science

5 questions. Try each one first, then open its answer.

  1. Question 1

    Chemical Reactions and Equations. Asked once: 2025 (same type asked 4 times)

    27 (A)
    Why do we balance a chemical equation? Name and state the law that suggests the balancing of a chemical equation? Balance the following chemical equation : Zn+H3PO4→Zn3(PO4)2+H2\mathrm{Zn + H_3PO_4 \rightarrow Zn_3(PO_4)_2 + H_2}

  2. Question 2

    Chemical Reactions and Equations. Asked once: 2025 (same type asked 4 times)

    21
    Define oxidation. Identify and name the substance oxidised in the following reaction : CuO+H2→Cu+H2O\mathrm{CuO + H_2 \rightarrow Cu + H_2O}

  3. Question 3

    Control and Coordination. Asked once: 2025 (same type asked 4 times)

    23
    Study the given diagram and write the type of movement exhibited by : (a) Root, and (b) Shoot, mentioning the stimulus in each case.

  4. Question 4

    Control and Coordination. Asked once: 2025 (same type asked 4 times)

    35 (a)
    (a) Analyse the given situations and interpret the possible reason for each : (i) Iodine deficiency in diet increases the possibility of a disease of swollen neck in a person. (ii) Some people in population may have very short heights (dwarfs). (iii) Thick facial hairs develop in boys at the age of 10-12 years. (b) Explain two reasons which necessitate the need of chemical communication in multicellular organisms.

  5. Question 5

    Control and Coordination. Asked once: 2026 (same type asked 4 times)

    4
    Human brain has various parts or regions that help in different actions, responses and coordination. From the following, identify the part responsible for precision of voluntary actions :

    Tap an option to check your answer.