Shadow

Umbra

Penumbra

Eclipse

Solar eclipse

Lunar eclipse

Mirror

Distance of object from the mirror

Optical fibre

VIBGYOR

formed only by opaque objects

darkest part of a shadow

lighter shade of shadow

incident which occurs when any astronomical object is partially or fully obscured due to placement of another astronomical object in the presence of light

Moon arriving between the sun and the earth

Earth arrving between the sun and the moon

polished or smooth surface which forms image by reflection

distance of the image from the mirror

total internal reflection

the band of visible light