Holography is a technique of
1). recording a permanent sharp two dimensional black and white or multicolor photograph
2). recording a permanent three dimensional multicolour photograph
3). recording a permanent three dimensional black and white photograph
4). recording a permanent three dimensional photograph of a given single colour or a multicolor
1. ?If there were no atmosphere, the length of the day on the earth will
4. Eclipses occur due to which optical phenomena
5. ?A galvanometer is converted into an ammeter when we connect a
7. Magnetic keepers are used to protect magnets from :
8. The substance which conducts current in the solid state is