Light Brightness Relationships for MCAT


Full Member
7+ Year Member
Apr 29, 2011
    So I know that power and light bulb brightness are directly proportional for MCAT purposes.

    However, because there are so many ways to write the power formula (P=IV = I^2 * R = V^2 / R), I was a bit confused and wanted to confirm whether the following is correct:

    If Potential = Constant*, bulb with LOWER RESISTANCE = Brighter

    If Current = Constant and potential is different#, bulb with HIGHER RESISTANCE = Brighter

    *Have a single bulb connected to battery; or have multiple bulbs connected in parallel

    #Have multiple bulbs connected in series

    Are there any other scenarios I should be aware of when determining brightness?
    Also, are there any sweeping statements that can be made about brightness for all scenarios (e.g., higher current = higher brightness, higher voltage = higher brightness?).
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