86. Who invented the first electric generator?
a) Michael Faraday
b) Thomas Edison
c) Nikola Tesla
d) George Westinghouse
87. Who discovered the phenomenon of radio waves?
a) Heinrich Hertz
b) James Clerk Maxwell
c) Guglielmo Marconi
d) Nikola Tesla
88. Who invented the first successful submarine?
a) John Philip Holland
b) Robert Fulton
c) David Bushnell
d) Cornelius Drebbel
89. Who discovered the law of specific heats?
a) Joseph Black
b) James Clerk Maxwell
c) Heinrich Hertz
d) Robert Boyle
90. Who invented the first successful electric motor?
a) Michael Faraday
b) Thomas Edison
c) Nikola Tesla
d) George Westinghouse