Physics Questions

The Camphor slowly dissolves in the water lowering the latter's surface tension in the immediate neighbourhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it. When after sometime the whole surface settles for the reduced tension, the movement of the camphor too short.

A periscope is an optical instrument that uses a system of prisms, lenses, or mirrors to reflect images through a tube.

Light from a distant object strikes the top mirror and is then reflected at an angle of 90 degrees down the periscope tube. At the bottom of the periscope, the light strikes another mirror and is then reflected into the viewer’s eye.

Hence, A periscope works by the principle of Total internal reflection.

An electric charge always flows from a body at higher potential to a body at a lower potential irrespective of the amounts of charges contained in them. In the question , no current flows. So there is no potential difference. 

In colder clouds: droplets formed by Bergeron mechanism. But, in many parts of the world the air is too warm for ice crystals to form. This being the case, rain and snow cannot develop following the Bergeron Process. Instead, tiny droplets form as they collide into one another creating larger and larger droplet, this is known as collision-coalescence process. So, warmer clouds are associated with this keyword.