1. [C] Sour and change blue litmus to red Property of acids is that it is sour in taste and change blue litmus to red.

    [C] Sour and change blue litmus to red
    Property of acids is that it is sour in taste and change blue litmus to red.

    See less
    • 1
  2. Air exerts pressure because of which banners and flags flutter.

    Air exerts pressure because of which banners and flags flutter.

    See less
    • 10
  3. (a)Take a piece of thin sheet of polythene from any used packaging bag. Hold it close to your mouth and suck-in the air. What do you observe? The sheet sticks to the lips and gets pulled inwards. Why is it so? That is because the air outside exerts pressure inwardly. (b) Take a balloon and blow it uRead more

    (a)Take a piece of thin sheet of polythene from any used packaging bag. Hold it close to your mouth and suck-in the air. What do you observe? The sheet sticks to the lips and gets pulled inwards. Why is it so? That is because the air outside exerts pressure inwardly.
    (b) Take a balloon and blow it up. Press it gently. You have to apply some force to press it. What is exerting pressure from inside? This is the air inside that exerts pressure.

    See less
    • 9
  4. The direction can be found by the following two methods– (a) Look at branches of a tree. The direction in which the branches are moving is the direction of wind. (b) Hold a light long piece of cloth. Observe the direction in which it sways. The direction in which the piece of cloth sways is the direRead more

    The direction can be found by the following two methods–
    (a) Look at branches of a tree. The direction in which the branches are moving is the direction of wind.
    (b) Hold a light long piece of cloth. Observe the direction in which it sways. The direction in which the piece of cloth sways is the direction of wind.

    See less
    • 9