19.
Penicillin was discovered by
Answer : B. Alexander Fleming
20.
The carbon filament is invented by
Answer : D. Edison
21.
Who is the father of discoveries
Answer : D. Archimedes
22.
Recording of sound on tapes was first invented by
Answer : C. Poulsen
23.
Electrons were discovered by
Answer : D. J.J.Thomson
24.
who discovered the principle of lever?
Answer : B. Archimedes