PYQ Vault

Day 179: CBSE Class 10 Science

5 questions (11 parts). Try each one first, then open its answer.

  1. Question 1 (case study, 4 parts)

    Electricity. Asked once: 2023 (same type asked 4 times)

    Consider the following electrical circuit diagram in which nine identical resistors of 3 Ω3\,\Omega each are connected as shown. If the reading of the ammeter A1\mathrm{A_1} is 1 ampere, answer the following questions :
    39 (a)
    What is the relationship between the readings of A1\mathrm{A_1} and A3\mathrm{A_3} ? Give reasons for your answer.
    39 (b)
    What is the relationship between the readings of A2\mathrm{A_2} and A3\mathrm{A_3} ?
    39 (c)
    Determine the reading of the voltmeter V1\mathrm{V_1}.
    39 (c) OR
    Find the total resistance of the circuit.

  2. Question 2

    Heredity. Asked once: 2023 (same type asked 4 times)

    Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the options given below.
    18
    Assertion (A) : In humans, if gene (B) is responsible for black eyes and gene (b) is responsible for brown eyes, then the colour of eyes of the progeny having gene combination Bb, bb or BB will be black only. Reason (R) : The black colour of the eyes is a dominant trait.

    Tap an option to check your answer.

  3. Question 3 (case study, 4 parts)

    How do Organisms Reproduce?. Asked once: 2022 (same type asked 4 times)

    The modes by which various organisms reproduce depend on the body design of the organisms. In asexual reproduction, a single individual parent produces offsprings without the involvement of gametes. This method is a common means of increasing the offsprings rapidly under favourable conditions. Asexual reproduction occurs mostly in unicellular organisms, some plants and certain simple multicellular animals.
    15 (a)
    State the name of the organism in which binary fission takes place in a definite orientation. Also name the disease caused by this organism.
    15 (b)
    List any two advantages of producing plants through vegetative propagation.
    15 (c) (i)
    Explain the process of budding in Hydra.
    15 (c) (ii)
    What happens when (I) a spirogyra filament matures and attains a considerable length, and (II) a sporangia in Rhizopus bursts on maturation ?

  4. Question 4

    Acids, Bases and Salts. Asked once: 2023 (same type asked 3 times)

    32
    (a) How is a universal indicator better than litmus solution ? (b) State two features of pH scale. (c) Why should we not add water to a concentrated acid ?

  5. Question 5

    Acids, Bases and Salts. Asked once: 2023 (same type asked 3 times)

    28 (a)
    A substance ‘X’ is used as a building material and is insoluble in water. When it reacts with dil. HCl, it produces a gas which turns lime water milky. (i) Write the chemical name and formula of ‘X’. (ii) Write chemical equations for the chemical reactions involved in the above statements.