Questions

Helioseismology is the study of the solar interior using observations of waves on the Sun's surface. It has done much to improve our understanding of the interior of the Sun, testing the physical inputs used to model stellar interiors and providing a detailed map of the Sun's structure and internal rotation.

Electrical Pressure is also called as Voltage. Voltage is measured in Volts.

Volt : A unit of electrical pressure or Voltage is called Volt.

One volt is the amount of pressure required to cause one ampere of current to flow against one ohm of resistance.

Voltage is also referred to as Electromotive Force or Electrical Potential or Electrical Pressure.

Sea appears blue in colour due to the scattering of the rays when they hit water molecules

Here are the differences between Diamond and Graphite :

From the above analysis, Diamond is harder than Graphite because of the difference of crystalline structures.