Friday, June 25

Spherical Mirrors

A spherical mirror is a mirror which has the shape of a piece cut out of a spherical surface. A spherical mirror is simply a piece cut out of a reflective sphere. Its center of curvature, C, is the center of the sphere it was cut from. R, the mirror's radius of curvature is the radius of the sphere. The focal point F (the point where parallel rays are focused) is located half the distance from the mirror to the center of curvature.

Types of Spherical Mirrors:

  • Concave Mirrors
  • Convex Mirrors
Concave Mirror: If the mirror's inside surface is reflective, the mirror is concave.Concave mirrors can form either real or virtual images, depending on where the object is. The Image below is an example of Concave Mirror.

Convex Mirror: If the mirror's outside surface is reflective, it's a convex mirror. A convex mirror can only form virtual images. A real image is an image that the light rays from the object actually pass through; a virtual image is formed because the light rays can be extended back to meet at the image position, but they don't actually go through the image position.The Image below is an example of Convex Mirror

Tuesday, June 22


Minerals are inorganic nutrients. They include both metallic and non-metallic elements, which are taken by the body in the form of salts. There are 24 elements that are used in our body. They have various functions such as formation of tissues such as the bone, conduction of nerve impulses, formation of RBCs, etc. There are eight major elements required by man and the others are needed in traces. The major elements are sodium, chlorine, potassium, calcium, phosphorus, sulphur and magnesium. Some of the trace elements or microelements are fluorine, zinc, copper, iodine, iron, manganese, chromium, cobalt, etc. However, they are all important for the well-being of the human body. All the minerals are basically obtained from the plants as they absorb these minerals from the soil.