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Deepika Mishra

Graphic Designing
Graphic Designing
2 years ago

87. When was vacuum tube invented? a. 1900 b. 1906 c.1910 d.1880

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Abhishek Mishra

2 years ago

Option B is correct, Explanation - British engineer John Ambrose Fleming invents and patents the thermionic valve, the first vacuum tube.

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Aryan Bind

2 years ago

Answer b (19

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Aryan Bind

2 years ago

b.1906 is correct

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