Consider the following statements. An ordinary light bulb has a rather short life because the 1. Filament wire is not uniform. 2. Bulb cannot be evacuated completely. 3. Wires supporting the filament melt at high temperatures. Which of the above statements are correct?
(A) 1 and 3
(B) 2 and 3
(C) 1 and 3
(D) 1, 2 and 3
Important Facts
Reasons for short bulb life: non-uniform filament, incomplete vacuum (oxidation), and melting of support wires.
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