Bangla Note of Physics 1st paper for HSC
The first law of thermodynamics is a version of the law of conservation of energy, specialized for thermodynamical systems. It is usually formulated by stating that the change in the internal energy of a closed system is equal to the amount of heat supplied to the system, minus the amount of work done by the … Read more
Last Updated: March 19, 2026 at 8:55 pmThermal radiation is electromagnetic radiation produced by the thermal motion of charged particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The mechanism is that bodies with a temperature above absolute zero have atoms or molecules with kinetic energies which are changing, and these changes result in charge-acceleration and/or … Read more
Last Updated: September 23, 2018 at 6:48 pmRadiation heat transfer is concerned with the exchange of thermal radiation energy between two or more bodies. Thermal radiation is defined as electromagnetic radiation in the wavelength range of 0.1 to 100 microns (which encompasses the visible light regime), and arises as a result of a temperature difference between 2 bodies. No medium need exist between the … Read more
Last Updated: September 23, 2018 at 6:48 pmA snowman, glass of water and steam might look very different but they are made of the same stuff! Just like any substance, water can exist in three different forms, called states: solid, liquid and gas. The state will change when the substance is heated. Change of State As a solid, a substance has a … Read more
Last Updated: September 23, 2018 at 6:48 pmA snowman, glass of water and steam might look very different but they are made of the same stuff! Just like any substance, water can exist in three different forms, called states: solid, liquid and gas. The state will change when the substance is heated. As a solid, a substance has a fixed volume and … Read more
Last Updated: March 19, 2026 at 11:48 pmThe second law of thermodynamics states that the entropy of an isolated system never decreases because isolated systems spontaneously evolve towards thermodynamic equilibrium—the state of maximum entropy. Equivalently, perpetual motion machines of the second kind are impossible. The second law is an empirically validated postulate of thermodynamics, but it can be understood and explained using … Read more
Last Updated: May 21, 2019 at 3:31 amThe second law of thermodynamics states that the entropy of an isolated system never decreases, because isolated systems spontaneously evolve towards thermodynamic equilibrium—the state of maximum entropy. Equivalently, perpetual motion machines of the second kind are impossible. The second law is an empirically validated postulate of thermodynamics, but it can be understood and explained using … Read more
Last Updated: September 23, 2018 at 6:48 pmSound wave is one of the most recognizable characters from the original Transformers line. He had an alternate mode – a microcassette recorder – and possessed a distinctive monotone, computerized voice. Soundwave is able to identify and jam transmissions across the entire energy spectrum, a talent that makes him suited to his position as Decepticon … Read more
Last Updated: March 19, 2026 at 11:48 pmSoundwave is one of the most recognizable characters from the original Transformers line. He had an alternate mode – a microcassette recorder – and possessed a distinctive monotone, computerized voice. Soundwave is able to identify and jam transmissions across the entire energy spectrum, a talent that makes him suited to his position as Decepticon Communications … Read more
Last Updated: March 19, 2026 at 11:48 pm