21. Gun was invented by:
(a) Bushnell
(b) Browning
(c) Plante
(d) Parson
22. Which of the following is the invention of Jarvik?
(a) Photography
(b) Photophone
(c) Artificial heart
(d) Colours photos
23. Name the inventor of Hydrometer?
(a) Baume
(b) Edison
(c) Edison
(d) Ester
24. Whose invention is incandescent lamp?
(a) Colt
(b) Waterman
(c) Bullock
(d) Hunt
25. Point out the inventor of Minor’s safety lamp.
(a) Goldmark
(b) Davy
(c) Spencer
(d) Richter
26. What is invented by Yale?
(a) Parachute
(b) Tan
(c) Lamp
(d) Cylinder lock
27. Mention the inventor of electric locomotive.
(a) Bell
(b) Vail
(c) Hoe
(d) Watt
28. Who is the inventor of the practical locomotive?
(a) Stephenson
(b) Harvey
(c) Plante
(d) Barly
29. Whose invention is power loom?
(a) Woods
(b) Cartwright
(c) Edison
(d) Marconi
30. Name the inventor of Dynamic loudspeaker.
(a) Talbot
(b) Colt
(c) Kellogg Pice
(d) Harrison