1. Who invented Vitamin A ?

Answer: Mc Collum and M.Davis of U.S.A. in 1913

2. Who invented Logarithms ?

Answer:

John Napier (Scotland) invented Logarithm

3. Who invented by Electric Lamp ?

Answer: Thomas Alva Edison of U.S.A. in 1879

4. Who invented Transistor ?

Answer: Bardeen, Shockley & Britain of U.S.A. in 1948

5. Who invented Calculus ?

Answer: Newton of Britain in 1670.

6. Who invented Steam Engine (Condenser)

Answer: James Watt of Britain in 1765

7. Who invented Aeroplane

Answer: Orville & Wilbur Wright in 1903