magnetic effects of electric current

• A solenoid is an insulated copper wire wrapped closely in the shape of a cylinder with many circular turns.
• The field lines inside the solenoid are in the form of parallel straight lines.
• The law of conservation of mass states that, "The matter can neither be created nor be destroyed in a chemical reaction".
• The total mass of reactants equals the total mass of products in a chemical reaction.
• Balancing a chemical equation involves writing the chemical equation, counting the number of atoms of each element on both the sides of the chemical equation, equalizing the number of the atoms of element which has the maximum number by putting in front of it, and equalizing all the atoms of elements on reactant and product side by adding coefficient in front of it.
• The physical states of reactants and products can be written in a chemical equation.
• Necessary conditions of temperature, pressure or catalyst can be written above or below the arrow in a chemical equation.
• Combination reaction is a type of chemical reaction in which two or more reactants combine to form a single product.
• Exothermic reactions are reactions in which heat is released along with formation of products.
• Decomposition reaction is a type of chemical reaction in which a compound splits into two or more simpler substances.
• Electrolytic decomposition is a type of decomposition reaction in which decomposition is carried out by passing electricity.
• Photolytic decomposition is a type of decomposition reaction in which decomposition is carried out in presence of sunlight.
• The symbols and formulae of the substances formed (products) are written on the right hand side of the equation, with a plus sign (+) between them.
• The electric current is defined as the rate of flow of electric charge through any cross-section of a conductor.
• Electric current is a scalar quantity.
• Ampere is the SI unit of current.
• If one Coulomb of charge flows through any cross-section of a conductor in one second, then current through it is said to be one ampere.
• The closed path along which an electric current flows is called an ‘electric circuit’.
• Conventionally, the direction of motion of positive charges through the conductor is taken as the direction of current.
• An electrochemical or voltaic cell is a device which converts chemical energy into electrical energy.
• A galvanometer is a device to detect current in an electric circuit.
• An ammeter is a device to measure current in a circuit.
• A rheostat is a variable resistor used to regulate current without changing the source of voltage.
• Resistance of a uniform metallic conductor is directly proportional to the length of the conductor.
• An arrow sign (→) is put between the reactants and the products in a chemical equation.
• The physical states of the reactants and products are also mentioned in a chemical equation.
• A chemical equation which simply represents the symbols and formulas of reactants and products taking part in the reaction is known as skeletal chemical equation for a reaction.
• The image formed by a convex lens is highly diminished, point-sized, real and inverted at infinity.
• Between infinity and the focus of the lens, the image is diminished, real and inverted.
• Between the focus of the lens and 2F, the image is diminished, real and inverted.
• At 2F, the image is the same size as the object, real and inverted.
• Between F and 2F, the image is enlarged, real and inverted.
• At focus F, the image is infinitely large or highly enlarged, real and inverted.
• Between focus F and the optical centre O of the lens, the image is enlarged, real and inverted.
• On the same side of the lens as the object, the image is enlarged, virtual and erect.
• Between infinity and the focus of the lens, the image is diminished, virtual and erect.
• Between the focus of the lens and 2F, the image is diminished, virtual and erect.
• At 2F, the image is the same size as the object, virtual and erect.
• Between F and 2F, the image is enlarged, virtual and erect.
• At focus F, the image is infinitely large or highly enlarged, virtual and erect.