10th SCIENCE

Introduction Pollution in Ganga The river Ganga is used as a sewage dump for more than 100 cities stretching across Uttar Pradesh, Bihar and West Bengal. Dumping of untreated sewage,  excreta, and chemicals from industries increases the toxicity of the water. This makes it inhabitable for the flora and fauna in the river system. In 1985 the GAP (Ganga Action Plan) project was initialised to curb the poor quality of the water of river Ganges. Reduce, recycle and reuse The 3 R's to save the environment can be performed by each individual in our society: Reduce: Reducing our usage and wasteful habits. Eg. not wasting food, turning off the switches to save electricity, repairing leaky taps, reducing the amount of water used for bathing etc. Reuse:  Using things again and again instead of discarding them. For example, reusing plastic utensils and bottles. Many things cannot be recycled or require a lot of energy, instead, we can utilize them for other purposes. Re...

Why Conservation of Energy? Energy and its sources Energy is the ability to do work or the total power derived from our natural resources. The energy exists in many forms and can be converted from one form of energy into another. Energy in usable form is dissipated to the surroundings as less usable form. Energy is mainly derived from natural sources like the sun, oceans, fossil fuels, wind etc and is converted into electrical energy that we consume for our daily needs and benefits. What Is a Good Fuel? A good source of energy Sources can be classified as renewable and nonrenewable sources of energy. Any source of energy that does not get depleted or gets exhausted is considered a good source of energy and are usually called as renewable. Good fuel A good source of energy/fuel should be: Easily available (Easy to store and transport Able to perform large amounts of work per unit mass and volume Economical Fossil Fuels and Thermal Energy Conventional sources...

Field and Field Lines Magnet A magnet is a material that produces a field that attracts or repels other such materials of magnetic nature. Lodestone is a naturally occurring magnet. It attracts materials like Iron, Nickel, Cobalt etc. Two magnets attracting each other North and South Poles A magnet is always bipolar with poles named north and south poles. These two poles always exist together and can not be separated. North pole of a magnet is the side which points to Earth's geographic north when it is freely suspended. Like poles repel and unlike poles attract Similar to charges, the poles attract and repel. Like poles repel while unlike poles attract each other. Bar magnet A bar magnet is a rectangular object, made up of iron, steel or any other ferromagnetic substance, that shows permanent magnetic properties. It has two poles, a north and a south pole such that when suspended freely, the north pole aligns itself towards the geographic north pole of the Earth....

Current and Voltage Atomic Structure An atom has a positively charged nucleus and negatively charged electrons revolving around it. Valence electrons in metals are free to move within the conductor and constitute an electric current. Charge The charge is an intrinsic property of matter by virtue of which it can exert electromagnetic force. Interaction between charges Conductors and Insulators A substance which offers comparatively less opposition to the flow of current is known as conductors and substances which offer larger opposition are insulators. Electric Potential and Potential Difference The electric potential at a point is defined as work done in bringing a unit positive charge from infinity to that point. The potential difference between two points is defined as the difference in electric potentials at the two given points.   Models of Electric Current Electric Current(I) Flow of electric charges is called electric current, i.e,  I = Q t ...