PYQ Vault

Day 76: CBSE Class 10 Science

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

  1. Question 1 (case study, 4 parts)

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

    In life there are certain changes in the environment called ‘stimuli’ to which we respond appropriately. Touching a flame suddenly is a dangerous situation for us. One way is to think consciously about the possibility of burning and then moving the hand. But our body has been designed in such a way that we save ourself from such situations immediately.
    38 (i)
    Name the action by which we protect ourself in the situation mentioned above and define it.
    38 (ii)
    Write the role of (a) motor and (b) relay neuron.
    38 (iii) (A)
    What are the two types of nervous system in human body? Name the components of each of them.
    38 (iii) (B)
    Which part of the human brain is responsible for : (a) thinking (b) picking up a pencil (c) controlling blood pressure (d) controlling hunger

  2. Question 2

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

    39 (b)
    (i) State Ohm’s law and draw V-I graph for a conductor which follows Ohm’s law. Show that the slope of V-I graph gives resistance of conductor. (ii) Derive an expression for the equivalent resistance of a series combination of three resistors having resistances R1R_1, R2R_2 and R3R_3.

  3. Question 3

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

    32
    Resistance of a wire of length 1 m is 35 Ω35\,\Omega at 20°C. If the diameter of the wire is 0⋅20{\cdot}2 mm, determine the resistivity of the material of the wire at that temperature. How will the resistivity of the wire change if the length and diameter of the wire both are doubled ? Justify your answer. (Given that π=227\pi = \dfrac{22}{7})

  4. Question 4

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

    14
    The minimum number of identical bulbs of rating 4V; 6W, that can work safely with desired brightness, when connected in series with a 240 V mains supply is :

    Tap an option to check your answer.

  5. Question 5

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

    39 (A)
    (i) The given electric circuit is a part of an electrical device. Use the information given in the electric circuit diagram to calculate : (I) Potential difference across the ends of resistor R2\mathrm{R_2}. (II) Value of resistor R2\mathrm{R_2}. (III) Value of resistor R1\mathrm{R_1}. (ii) Write the factors on which resistance of a conductor depends and derive the formula for resistance of a given conductor.