PYQ Vault

Day 229: CBSE Class 10 Science

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

  1. Question 1

    Chemical Reactions and Equations. Asked once: 2024

    1
    Identify the product ‘X’ obtained in the following chemical reaction : CaCO3\mathrm{CaCO_3} →Δ\xrightarrow{\Delta} ‘X’ + CO2\mathrm{CO_2}

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  2. Question 2

    Control and Coordination. Asked once: 2026

    11 (a)
    State two differences between the act of chewing food and salivation on sight of food.

  3. Question 3 (case study, 4 parts)

    Electricity. Asked once: 2026

    Three students Shweta, Ayesha and Samridhi were performing an experiment to understand the factors on which the resistance of a conductor depends. Each one of them completed electric circuit with the help of a cell, an ammeter, a plug key and wire. Shweta put nichrome wire of length ‘l’ in the circuit and after plugging the key, noted current in the ammeter. Ayesha put nichrome wire of same thickness but twice the length i.e. ‘2*l*’ in the circuit and after plugging the key, noted current in the ammeter. Samridhi took copper wire of length ‘l’ and same thickness in the circuit and after plugging the key, noted current in the ammeter.
    38 (a)
    If the ammeter reading is X ampere with nichrome wire of length ‘l’, then what will be the ammeter reading if the length of nichrome wire is doubled with same area of cross-section ?
    38 (b)
    What happens to the ammeter reading if the area of cross-section of nichrome wire is doubled, keeping the length of wire ‘l’ the same ?
    38 (c)
    Define ‘resistivity’. Write its SI unit. Compare the resistivity of an alloy with its constituents metals.
    38 (c) OR
    Give reason : (i) Tungsten is used almost exclusively for making the filament of electric lamps. (ii) Conductors of bread-toasters are made of an alloy rather than a pure metal.

  4. Question 4

    How do Organisms Reproduce?. Asked once: 2024

    9
    Part(s) of a flower which attracts insects for pollination is (are)

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  5. Question 5

    Magnetic Effects of Electric Current. Asked once: 2023

    15
    The magnetic field inside a long straight current carrying solenoid :

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