Questions

It is a scheme across the river Rihand near Pipri in Mirzapur district of Uttar Pradesh

There are two types of water hardness: temporary and permanent hardness. Temporary hardness is due to the presence of calcium hydrogen carbonate Ca(HCO3)2(aq) and magnesium hydrogen carbonate Mg(HCO3)2(aq).

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.

Page swapping or page replacements are called page cannibalizing.