49.
In which decade was the telegraph invented?
A. 1810s B. 1840s
C. 1870s D. 1890s
Answer & Explanation
Answer: Option B
Explanation:
On May 24, 1844, Samuel Morse send his famous message, “What hath God wrought?”
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50.
What inspired reflecting road lights to be invented?
A. Car door reflecting mirrors
B. The light a cat’s eyes gave off on a fence
C. Sun light on steel posts on road sides
D. The sun light on the windshield
Answer & Explanation
Answer: Option B
Explanation:
In 1933, Englishman Percy Shaw was driving home when he saw a cat’s eyes reflecting. He had been headed straight towards a fence with the cat on it, but on the other side was a drop of hundreds of feet.
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51.
When were blue jeans invented?
A. 1900s B. 1860s
C. 1870s D. 1850s
Answer & Explanation
Answer: Option D
Explanation:
The first blue jeans were invented by tailor Levi Strauss, who invented tougher working pants for the miners of the California Gold Rush.
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52.
Who invented Electric Generator?
A. Sir Alexander Graham Bell
B. Michael Faraday
C. Alfred B. Nobel
D. Thomas Alva Edison
Answer & Explanation
Answer: Option B
Explanation:
No answer description available for this question. Let us discuss.
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53.
What device for new parents did Ann Moore invent in 1969?
A. Bottle warmer
B. Baby monitor
C. Disposable diaper
D. Infant carrier
Answer & Explanation
Answer: Option D
Explanation:
Ann got the idea for the Snugli infant carrier from the traditional African baby carriers she observed while a volunteer for the Peace Corps in Africa.
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54.
In which decade was the transistor invented?
A. 1940s B. 1950s
C. 1960s D. 1980s
Answer & Explanation
Answer: Option A
Explanation:
On December 23, 1947, William Shockley, Walter Brattain and John Bardeen, of Bell Labs, announced their discovery of the point-contact germanium transistor to management.
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55.
What Igor Sikorsky invented?
A. Hydroplane
B. Jet engine airplane
C. Helicopter
D. Glider
Answer & Explanation
Answer: Option C
Explanation:
Invented in 1939.
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56.
What Henry Bessemer invented?
A. Aluminum
B. Electroplating
C. Steel Converter
D. Steel rolling mill
Answer & Explanation
Answer: Option C
Explanation:
Invented in 1856.