1. Who invented Automatic rifle ?

Answer: John Browning of U.S.A. in 1918.

2. Who invented Transistor ?

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

3. Who invented Neutron bomb ?

Answer:

Samuel T. Cohen

4. Who invented Nylon ?

Answer:

Wallace Carothers

5. Who invented Vitamin A ?

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

6. Who invented Open Heart Surgery ?

Answer:

Dr. Daniel Hale Williams

7. Who invented Steam Engine ?

Answer: Thomas Savery of Britain in 1698