PYQ Vault

Day 113: CBSE Class 10 Science

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

  1. Question 1

    Electricity. Asked once: 2025 (same type asked 4 times)

    13
    A wire of length ‘l’ is gradually stretched so that its length increases to 3*l*. If its original resistance is R, then its new resistance will be :

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  2. Question 2

    Electricity. Asked once: 2024 (same type asked 4 times)

    34 (A)
    (i) State whether the currents and potential difference in all the bulbs will be same or different when in a circuit three bulbs of : (a) same wattage are connected in series. (b) same wattage are connected in parallel. (c) different wattage are connected in series. (d) different wattage are connected in parallel. (ii) Two identical resistors of 24 Ω24\,\Omega each are connected to a battery of 6 V. Calculate the ratio of the power consumed by the resulting combinations with (a) minimum resistance and (b) maximum resistance.

  3. Question 3

    Electricity. Asked once: 2026 (same type asked 4 times)

    39 (a)
    Study the given electric circuit in which 2 A electric current is flowing between points X and Y. (i) Using the battery, key, voltmeter and ammeter in this given electric circuit, redraw a circuit diagram in which 2 Ω2\,\Omega and 4 Ω4\,\Omega resistors are connected between X and Y in parallel combination. (ii) Circuit drawn by you, in which resistors are connected in parallel combination, calculate the electric current flowing through 4 Ω4\,\Omega resistor.

  4. Question 4 (case study, 4 parts)

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

    The most obvious outcome of the reproductive process is the generation of individuals of similar design, but in sexual reproduction they may not be exactly alike. The resemblances as well as differences are marked. The rules of heredity determine the process by which traits and characteristics are reliably inherited. Many experiments have been done to study the rules of inheritance.
    38 (i)
    Why an offspring of human being is not a true copy of his parents in sexual reproduction ?
    38 (ii)
    While performing experiments on inheritance in plants, what is the difference between F1\mathrm{F_1} and F2\mathrm{F_2} generation ?
    38 (iii) (A)
    Why do we say that variations are useful for the survival of a species over time ?
    38 (iii) (B)
    Study Mendel’s cross between two plants with a pair of contrasting characters. RRYY (Round Yellow) ×\times rryy (Wrinkled Green) He observed 4 types of combinations in F2\mathrm{F_2} generation. Which of these were new combinations ? Why do new features which are not present in the parents, appear in F2\mathrm{F_2} generation ?

  5. Question 5

    Heredity. Asked once: 2024 (same type asked 4 times)

    12
    A cross made between two pea plants produces 50% tall and 50% short pea plants. The gene combination of the parental pea plants must be

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