মাধ্যমিক

Ammeter and Voltmeter: Class 8 Science: Chapter 9   An ammeter and voltmeter are two important instruments used in electrical engineering and physics to measure the current and voltage in a circuit. They both work by measuring the electrical properties of a circuit and are essential tools for designing, troubleshooting, and repairing electrical systems. Ammeter An ammeter is an instrument used to measure the electric current in a circuit. It is typically connected in series with the circuit and measures the current flowing through it. The unit of measurement for current is the ampere (A), and an ammeter is calibrated in amperes. To measure the current in a circuit using an ammeter, the circuit must be interrupted, and the ammeter must be inserted in series with the componen...

Heat energy conversion in chemical reactions: Class 8 Science: Chapter 8 Heat energy conversion in chemical reactions is an essential aspect of chemistry. Chemical reactions that involve a change in temperature, whether endothermic or exothermic, can release or absorb heat energy. Heat energy can be converted into other forms of energy such as electrical, mechanical, or sound energy. In this paper, we will discuss heat energy conversion in chemical reactions and provide examples of chemical formulas. Endothermic Reactions Endothermic reactions are those reactions that require the absorption of heat energy to occur. These reactions usually take place in cold environments and are characterized by a decrease in temperature. The heat energy is absorbed by the reactants during the reaction...