1. Who invented Transistor ?

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

2. Who invented Microphone ?

Answer:

Emile Berliner invented the first microphone in 1876.

3. Who invented Refrigerator ?

Answer:

Oliver Evans in 1805

4. Who invented Dynamo ?

Answer:

Hypolite Pixii of France in 1832

5. Who invented Vitamin D ?

Answer:

Edward Mellanby discovered Vitamin D while researching a disease called rickets in 1922

6. Who invented Steam Engine (Condenser)

Answer: James Watt of Britain in 1765

7. Who invented Proton ?

Answer:

Ernest Rutherford