Energy

Define mechanical energy and law of conservation of mechanical energy. Prove conversion of gravitational potential energy in to kinetic energy by the help of law of conservation of mechanical energy. Also draw graph between energy and height.

Solve the following crossword puzzle (1) Maximum energy generation in India is done using………….energy. (2)…………energy is a renewable source of energy. (3)Solar energy can be called…………energy. (4)………..energy of wind is used in winmills. (5)…………energy of water in dams is used for generation of electricity.

Some renewable sources of energy are given below : solar energy, tidal energy, biogas energy, hydel energy , OTEC, wind energy, geothermal energy, ocean wave energy. Which of the given sources are more reliable and consistent in availability.

As an electron makes a transition from an excited state to the ground state of a hydrogen like atom/ion (a) kinetic energy, potential energy and total energy decrease (b) kinetic energy decreases, potential energy increases but total energy remains same (c ) kinetic energy and total energy decrease but potential energy increases (d) its kinetic energy increases but potential energy and total energy decrease