BCA Semester 1: Physics - Forms of EnergyQ & A
Q(2013): (a) State Law of Conservation of Energy.
(b) Write the names of different forms of energy.
Law of Conservation of Energy: This law states that energy can neither be created nor be destroyed, but can change form. It means total energy of an isolated system cannot change. The total energy E of a system can change only by amounts of energy that are transferred to or from the system.
i.e. W = △E = △Emech + △Eth + △Eint
where △Emech = change in mechanical energy,
△Eth = change in thermal energy
△Eint = change in other type of internal energy of the system.
(b) Forms of Energy
|Type of Energy||Description|
|Kinetic||Due to motion of a body|
|Potential||Due to position or configuration of the body.|
|Mechanical||Sum of potential and kinetic energy of a body.|
|Electrical||Due to electrical field around a body.|
|Chemical||Due to atoms and molecules of a body|
|Magnetic||Due to magnetic field|
|Nuclear||Due to binding force between sub-atomic particles.|
|Gravitational||Due to gravitational Field|
|Radiant||Due to radiation including light|
|Thermal or Heat||heat energy due to difference in temperature|
|Intrinsic or Internal||Due to mass possessed by an object|
Q (2011): Does kinetic energy of a body depend upon direction of motion? Justify your answer.
Answer: No. Kinetic energy is a scalar quantity. It does not depend on the direction of motion. It depends on mass and magnitude of speed.