A particle having at least one dimension less than 10^-7 metre, is known as

The branch of Physics that deals with the motion of very small particles is called :

The size of particles being studied in 'nano-technology' is about

Which one of the following devices is used to cool the engine of the vehicles?

The ratio of the diameters of moon and earth is nearly

What was the fissionable material used in the bombs dropped at Nagasaki (Japan) in the year 1945?