Saturday 15th July 2023
    Difficulty: Medium

    Light bulbs (Quiz #239)

    Photo by <a href="https://unsplash.com/@vlisidis?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Terry Vlisidis</a>
    Photo by Terry Vlisidis (Unsplash)

    1. What did the first commercially produced light bulbs use as their filament?

    2. There are two methods by which most standard light bulbs are fitted into their sockets: BC and ES. "BC" stands for "bayonet clip". What does "ES" stand for?

    3. What percentage of the energy used by a traditional incandescent light bulb is actually converted into light?

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