1. Who invented Calculus ?

Answer: Newton of Britain in 1670.

2. Who invented Ball-Point Pen ?

Answer: John J. Loud of U.S.A. in 1888

3. Who invented Periodic table ?

Answer:

Dmitri Mendeleev invented Periodic Table

4. Who invented Steam Engine ?

Answer: Thomas Savery of Britain in 1698

5. Who invented Radar ?

Answer:

Sir Robert Watson-Watt

6. Who invented by Electric Lamp ?

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

7. Who invented X-ray ?

Answer: W.K. Roentgen of Germany in 1895.