1. Who invented Laser ?

Answer:

Charles H. Townes

2. Who invented Gramophone ?

Answer:

Emile Berliner in 1887.

3. Who invented Safety Pin ?

Answer: Walter Hunt of U.S.A. in 1849

4. Who invented paper ?

Answer:

Cai Lun

5. Who invented Submarine ?

Answer:

John Philip Holland

6. Who invented Radar ?

Answer:

Sir Robert Watson-Watt

7. Who invented Atomic Bomb ?

Answer: J. Robert Oppenheimer of U.S.A. in 1945