Correct Answer – (2) Surface Tension
Explanation: Raindrops start out as round high in the atmosphere as water collects on dust and smoke particles in clouds. But as raindrops fall, they lose their rounded shape. A raindrop falling through the atmosphere forms as a roughly spherical structure due to the surface tension of water. This surface tension is the “skin” of a body of water that makes the molecules stick together. The cause is the weak hydrogen bonds that occur between water molecules.

Correct Answer – (2) electromagnetic waves
Explanation: Electromagnetic radiation is the certain radiant energy relcased by clectromagnetic processes. It consists of clectromagnetic waves which are synchronized oscillations of clectric and magnetic ficlds that propagate at the speed of light through a vacuum.

Correct Answer – (4) graphite
Explanation: Graphite has a tendency to behave very much like a metal because the carbon molecules arange themselves into a lattice structure. The crystal lattice is the same orientation that metal forms, and it allows the free-movement of electrons, making it a good characteristics electrical conductor. The possesses by the graphite for conduction is far better than the dry air paper and kerosene and that’s what makes it a good conductor.