1. Who invented Automatic rifle ?

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

2. Who invented Air Conditioning ?

Answer:

Willis Carrier in 1902

3. Who invented Bakelite ?

Answer: Leo H. Baekeland of Belgium in 1907.

4. Who invented Proton ?

Answer:

Ernest Rutherford

5. Who invented Gramophone ?

Answer:

Emile Berliner in 1887.

6. Who invented Calculus ?

Answer: Newton of Britain in 1670.

7. Who invented Stethoscope ?

Answer: Laennec of French in 1819.