Category: Important Questions
How does ice crack open pipes made of strong metals. Water has the property of expanding by about one- ninth of its volume when it freezes. Ice, therefore occupies …
How does salt gets dissolved in water? Water is a polar molecule having both positive and negative ends. A salt crystal is also held together by the force of …
How does a heater warm up the whole room? The air above the heater becomes warm. Warm air expands and rises up tin to the air. Cool air comes …
How do we hear sounds? The human ear has three main parts—the outer ear, middle ear and inner ear. When a sound or noise is produced, the air particles …
How can you see different programmes on different channels? Each T.V. station uses a different signal with a different frequency than other TV stations. Our T.V. antenna catches all …
How are minerals extracted from the earth? Minerals occur in the earth’s crust through-out the world. Depending upon the nature and location of the minerals, various methods are used …
Now did the system of counting begin? The cave man used, his fingers, or toes for counting. The word ‘digit’ is derived from the Latin word digitus meaning finger. …
How do the scientists know what the sun is made of when nobody has ever been to sun? Sun is a huge ball of hot gases that nobody can …
