Science

Question: What is an election? State its relative mass and charge. Answer: The negatively charged particle found in the atoms of all elements is known as electron. The relative mass of an election is 1/1840 u & charge is – 1 (minus one). Question: What is the absolute mass & …

NCERT 9th Class (CBSE) Science: Sound Quiz 23 Multiple Choice Questions related to NCERT 9th Class (CBSE) Science: Sound Quiz The way our brain interprets the frequency of an emitted sound is called the pitch. The quality or timber of sound helps us to distinguish one sound from another having …

NCERT 9th Class (CBSE) Science: Energy and Work Quiz 19 Multiple Choice Questions related to NCERT 9th Class (CBSE) Science: Energy and Work Quiz It states that energy can neither be created nor destroyed. It can only change its form. The winning team does work. The work is equal to …

Sound – 9th Class NCERT CBSE Science Chapter 12 Question: Can sound travel through: Carbon Water Answer: yes yes Question: Can sound travel through vacuum? Answer: No, sound cannot travel through vacuum. Question: Name the type of waves which are used by astronauts to communicate with one another on moon (or in …

Question: Define law of conservation of mass. Answer: In a chemical reaction mass can neither be created nor destroyed. E.g., 2Na + Cl2 —–> 2NaCl 2 x 23 + 2 x 35.5 ——> 2(23 + 35.5) Question: Explain law of constant proportion. Answer: In a chemical substance the elements are always …

Question: Does work done depend upon the velocity of the body. Answer: No. Question: State the law of conservation of energy. Answer: It states that energy can neither be created nor destroyed. It can only change its form. Question: In a tug-of-war one team gives way to the other. What …

NCERT 9th Class (CBSE) Science: Atoms and Molecules Quiz 20 Multiple Choice Questions related to NCERT 9th Class (CBSE) Science: Atoms and Molecules Quiz: In a chemical substance the elements are always present in definite proportions by mass. E.g., In water, the ratio of the mass of hydrogen to the …

NCERT 8th Class (CBSE) Science: Pollution of Water and Air – Quiz 23 Multiple Choice Questions related to NCERT 8th Class (CBSE) Science: Pollution of Water and Air – Quiz: Water is renewed continuously in nature through the water cycle. Water containing harmful impurities is said to be polluted. Pollution occurs …

Question: What harm can dumping of untreated sewage into a river cause? Answer: Untreated sewage from homes is often disposed off into rivers. These wastes contain many harmful microorganisms – bacteria, viruses, fungi and parasites that cause diseases such as diarrhoea, dysentery, cholera, typhoid and jaundice. Question: Why is hot water …

NCERT 8th Class (CBSE) Science: Chemical Effects of Electric Current – Quiz 23 Multiple Choice Questions related to NCERT 8th Class (CBSE) Science: Chemical Effects of Electric Current – Quiz: The flow of electrons constitutes an electric current. Conventional current flows from positive to negative terminal; electronic current lows from negative …