31. Who invented the gas mantle?
(a) Wellsbach
(b) Spenser
(c) Berliner
(d) Colt
32. Microphone is the invention of:
(a) Shrapnel
(b) Berliner
(c) Berliner
(d) Kirchhoff
33. Who is the inventor of motorcycle?
(a) De Forest
(b) Bell
(c) Daimler
(d) Harrison
34. Which is the invention of Jenkins?
(a) Safety-pin
(b) Pistol
(c) Nylon
(d) Movie machine
35. Who invented the talking movie?
(a) Warner Brother
(b) Harrison
(c) Colt
(d) Bell
36. Who invented the paper machine?
(a) Hoe
(b) Bell
(c) Dickinson
(d) Marconi
37. The inventor of the parachute is:
(a) Blanchard
(b) Marconi
(c) Richter
(d) Berliner
38. Who invented the fountain pen?
(a) Waterman
(b) Burson
(c) Colt
(d) Spenser
39. Which of the following is Galileo’s invention?
(a) Telephone
(b) Pendulum
(c) Frequency
(d) Tank
40. Which of the following is Edison’s invention?
(a) Photo phone
(b) Phonograph
(c) Photography
(d) Telephone