PYQ Vault

Day 83: CBSE Class 10 Science

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

  1. Question 1

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

    22 (b)
    Heat produced per second due to a current in a resistor of 4 Ω4\,\Omega is 400 joules. Calculate the potential difference across the resistor.

  2. Question 2 (case study, 4 parts)

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

    As shown in the diagram, an electric circuit consisting of an ammeter, a voltmeter, 4 cells of 1⋅51{\cdot}5 V each, a plug key with a gap XY was set up. Voltmeter and ammeter readings were recorded in the observation table for four arrangements as given below : Arrangement No. 1 – only resistor R1\mathrm{R_1} in gap XY Arrangement No. 2 – only resistor R2\mathrm{R_2} in gap XY Arrangement No. 3 – Resistors R1\mathrm{R_1} and R2\mathrm{R_2} in series in gap XY Arrangement No. 4 – Resistors R1\mathrm{R_1} and R2\mathrm{R_2} in parallel in gap XY Based on the observations, four V – I graphs A, B, C and D as shown in figure were drawn. Study these graphs.
    39 (a)
    Which one of the graphs represents the series combination of R1\mathrm{R_1} and R2\mathrm{R_2} ?
    39 (b)
    Which one of these graphs represents the parallel combination of R1\mathrm{R_1} and R2\mathrm{R_2} ?
    39 (c) (i)
    Show an arrangement of three resistors, each of resistance 10 Ω10\,\Omega, so that the combination has a resistance of 15 Ω15\,\Omega. Give justification for your answer.
    39 (c) (ii)
    A battery of 6 V is connected with a series combination of five resistors of 0⋅1 Ω0{\cdot}1\,\Omega, 0⋅2 Ω0{\cdot}2\,\Omega, 0⋅3 Ω0{\cdot}3\,\Omega, 0⋅4 Ω0{\cdot}4\,\Omega and 0⋅5 Ω0{\cdot}5\,\Omega. How much current would flow through the 0⋅3 Ω0{\cdot}3\,\Omega resistor ? Justify your answer.

  3. Question 3

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

    30
    The lowest part of the ear called earlobe, is closely attached to the side of the head in some of us (Figure ‘X’), and not in others, called free earlobe (Figure ‘Y’). Attached and free earlobes are two variants found in human populations. The gene for free earlobe is dominant over attached earlobes. (a) A man with attached earlobes marries a woman having free earlobes. 50% of their children have free earlobes and 50% have attached earlobes. Explain the inheritance of this trait and write the trait combinations of the progeny. (b) Write the gene combinations of the father and the mother in the above case.

  4. Question 4 (case study, 4 parts)

    How do Organisms Reproduce?. Asked once: 2024 (same type asked 4 times)

    Asexual reproduction involves a single parent to produce offsprings without the formation of gametes. It occurs by the following ways : Fission, Budding, Fragmentation, Spore formation and Regeneration. In one of the methods like regeneration, Planaria A is cut horizontally into three pieces – L, M and N and Planaria B is cut vertically into two equal halves – O and P.
    38 (a)
    Which of the cut pieces of the two Planaria could regenerate to form a complete organism ?
    38 (b)
    Give an example of another organism which follows the same mode of reproduction as Planaria.
    38 (c)
    What is the meaning of ‘development’ in regeneration ?
    38 (c) OR
    Differentiate between regeneration and fragmentation.

  5. Question 5

    Metals and Non-metals. Asked once: 2024 (same type asked 4 times)

    2
    The number of shells required to write the electronic configuration of Potassium (At. No. 19)

    Tap an option to check your answer.