1. Which plane mirror is used to make periscope?

2. An optical instrument used to see through an object that is occluded from the direct line of sight is called a periscope.

3. A periscope consists of two plane mirrors placed at an angle of 45°.

4. When light falls on one of the mirrors then after reflection from the first mirror it falls on the second mirror which further reflects it and falls on the eye of the observer.

The Constituent Assembly held its first meeting on Dec.9,1946. The meeting was attended by 211 members. Dr. Sachchidanand Sinha, the oldest one,was elected as the temporary president of the assembly. Later on, Dec.11,1946, Dr. Rajendra Prasad and H.C. Mukherjee were elected as the President and vice-president of the assembly.Sir B N Rau was appointed as the Constitutional Advisor in the assembly.

A torch emits a divergent light beam, where light rays spread out as they move away from the source. This spreading allows the flashlight to illuminate a wider area, making it useful for various tasks. Divergent beams are common in flashlights, ensuring efficient coverage and visibility in the dark.

All (Mineral - Mining area) are correctly matched.

(A) Rock Phosphate - Jhamar Kotra

(B) Manganese - Kala Khunta

(C) Garnet - Rajmahal

(D) Iron Ore - Morija Dabla