Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?
The objects through which electricity can pass easily are called conductors and other one from which electricity cannot pass through them are called insulators. For a bulb to glow, there should be presence of conductors. Here bulb is not glowing if we use an eraser at the place of pin because eraser is an insulator of electricity. So, here circuit is not complete, so the bulb will not glow.
Draw (a) a leaf, (b) a taproot and (c) a flower, you have studied for Table 7.3.
You are given an iron strip. How will you make it into a magnet?
Name two foods each rich in:
(a) Fats
(b) Starch
(c) Dietary fibre
(d) Protein
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
Tick (√) the statements that are correct.
(a) By eating rice alone, we can fulfill nutritional requirement of our body. ( )
(b) Deficiency diseases can be prevented by eating a balanced diet. ( )
(c) Balanced diet for the body should contain a variety of food items. ( )
(d) Meat alone is sufficient to provide all nutrients to the body. ( )
List all items known to you that float on water. Check and see if they will float on an oil or kerosene.
Name the part of the plant which produces its food. Name this process.
Why can a pace or a footstep not be used as a standard unit of length?
Given below are the names of some objects and materials:
Water, basket ball, orange, sugar, globe, apple and earthen pitcher Group them as:
(a) Round shaped and other shapes
(b) Eatables and non eatables
Name two items that are made from coconut fibre.
It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.
Fill in the blanks :
(a) A device that is used to break an electric circuit is called _______________.
(b) An electric cell has _______________ terminals.
A drawing sheet changes when you draw a picture on it. Can you reverse this change?
What is sieving? Where is it used?
How will you show that air is dissolved in water?
Discuss :
(a) Is garbage disposal the responsibility only of the government?
(b) Is it possible to reduce the problems relating to disposal of garbage?
How are clouds formed?
The height of a person is 1.65 m. Express it into cm and mm.
Arrange the following lengths in their increasing magnitude:
1 metre, 1 centimetre, 1 kilometre,1 millimetre.
How will you prove that air supports burning?