Science- Work, Power and Energy

A microphone converts:

Which of the following energy change involves frictional force?
i. Potential energy to sound energy
ii. Chemical energy to heat energy
iii. Kinetic energy to heat energy
iv. Chemical energy to heat energy
Choose the correct option among the following:

An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass 3.5 kg. Both spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same:

Two objects of masses 1 x 10-3kg and 4 x 10-3 kg have equal momentum. What is the ratio of their kinetic energies?

The work done on an object does not depend upon the:

A body is falling from a height h. After it has fallen to a height of h/2, it will possess:

The type of energy possessed by a simple pendulum, when it is at the mean position is:

A man of mass 50 kg jumps to a height of 1 m. His potential energy at the highest point is(g = 10 m/s2):

The form of energy possessed by a flying bird is:

In the dams water is stored in the high reservoirs and then made to fall down. This falling water then rotates the turbines to generate electricity. In this energy conversion process can you tell the initial and final energies respectively?