Disclosing this, Kusum Lata said, “I am happy that I did not spend much on this aid and this was also highlighted by the chief guest on the occasion. The aid explains different ‘principles of light’ very clearly.”

Reena Rai, Secretary, Education, Delhi, was the chief guest. Kusum was awarded with a golden plaque along with a cash prize of Rs 1,500 and a very expensive book describing various science experiments along with a certificate.

Earlier, this aid was declared first at the district-level science exhibition. The aid explains different type of functioning of “Parallel rays”. Made of a mere shoe-box and a few convex and concave lenses and mirrors, Kusum depicts very clearly as to how parallel rays fall on a rough surface, how they move on a concave mirror. Not only this, but she also explained to the children of senior classes along with teachers about the “laws of reflection” and ‘laws of refraction” and how false image comes into existence, binocular vision, total internal reflection etc. Her teaching aid is also helpful in explaining the “Myopia defect among children”. She also explains in detail as how it is removed with concave lenses in children and with convex in elders. Adding to these aids is “Periscope’ prepared by a thermocol glass. It tells as how one views enemies in sub-marine.