Science
Science is the systematic study of the natural world through observation, experimentation, and analysis. It involves forming hypotheses, conducting experiments, collecting data, and analyzing results to develop conclusions and theories. The primary aim of science is to understand how the universe works, from the smallest particles to the vastness of space.
Science is divided into several branches:
- Physical Sciences – These include physics, chemistry, astronomy, and geology, and they focus on understanding the laws of matter and energy.
- Life Sciences –These focus on living organisms and include fields like biology, ecology, and medicine.
- Social Sciences – These study human behavior and societies, such as psychology, sociology, and economics.
- Environmental Science –The study of the environment and the impact of human activity on it.
Scientific discoveries and advancements often lead to new technologies that improve our quality of life. Science helps answer fundamental questions about existence, provides solutions to real-world problems, and drives progress in many areas of life.
Question related to Science
- Which state of matter has a definite volume but no definite shape?
- Which one of the following has the highest compressibility?
- We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror? What is the nature of the image? Is the image larger or smaller than the object?
- What are anhydrous and hydrated salts? Explain with a suitable example of each.
- The force of attraction between particles is strongest in:
- Differentiate between metal and non-metal on the basis of their chemical properties.
- What is the magnitude of the gravitational force between the Earth and a 1 kg object on its surface? (Mass of Earth = 6 × 10²⁴ kg, Radius of Earth = 6.4 × 10⁶ m)
- The volume of a 500 g sealed packet is 350 cm³. Will the packet float or sink in water if the density of water is 1 g/cm³? What will be the mass of the water displaced by this packet?
- A solution of a substance ‘X’ is used for whitewashing. (i) Name the substance ‘X’ and write its formula. (ii) Write the reaction of the substance ‘X’ named in (i) above with water.
- Which of the following pairs will give displacement reactions? (a) NaCl solution and copper metal (b) MgCl₂ solution and aluminium metal (c) FeSO₄ solution and silver metal (d) AgNO₃ solution and copper metal
- How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
- Define law of conservation of mass.
- The human eye forms the image of an object at its (a) cornea. (b) iris. (c) pupil. (d) retina.
- Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
- Identify the acid and the base from which sodium chloride is obtained. Which type of salt is it? When is it called rock salt? How is rock salt formed?
- A white powder is added while baking cakes to make it soft and spongy. Name its main ingredients. Explain the function of each ingredient. Write the chemical reaction taking place when the powder is heated during baking.
- The distance between two stations is 240 km. A train takes 4 hours to cover this distance. Calculate the speed of the train.
- Electric appliances like electric -press, toaster, fans etc are connected to electric mains through three-pin plug. Why?
- Which component of blood helps to fight infection?
- The volume of 50 g of a substance is 20 cm³. If the density of water is 1 g/cm³, will the substance float or sink?
- What happens at the synapse between two neurons?
- Why does an aqueous solution of an acid conduct electricity ?
- Akhtar, Kiran and Rahul were riding in a motorcar that was moving with a high velocity on an expressway when an insect hit the windshield and got stuck on the windscreen. Akhtar and Kiran started pondering over the situation. Kiran suggested that the insect suffered a greater change in momentum as compared to the change in momentum of the motorcar (because the change in the velocity of the insect was much more than that of the motorcar). Akhtar said that since the motorcar was moving with a larger velocity, it exerted a larger force on the insect. And as a result the insect died. Rahul while putting an entirely new explanation said that both the motorcar and the insect experienced the same force and a change in their momentum. Comment on these suggestions.
- Explain different types of motion with examples.
- When does an electric short circuit occur?
- What determines the rate at which energy is delivered by a current?
- Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?
- At the time of short circuit, the current in the circuit (a) reduces substantially. (b) does not change. (c) increases heavily. (d) vary continuously
- Why do HCl, HNO3, etc show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character ?
- Write the frequency of alternating current (AC) in India. How many times per second it changes its direction?