A circuit contains a 48-V battery and a single light bulb

Chapter , Problem 125

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A circuit contains a 48-V battery and a single light bulb whose resistance is 240 V. A second, identical, light bulb can be wired either in series or in parallel with the fi rst one (see the fi gure). Concepts: (i) How is the power P that is delivered to a light bulb related to the bulbs resistance R and the voltage V across it? (ii) When there is only one bulb in the circuit, what is the voltage across it? (iii) The more power delivered to a bulb, the brighter it is. When two bulbs are wired in series, does the brightness of each bulb increase, decrease, or remain the same relative to the brightness of the bulb in the single-bulb circuit? (iv) When * two bulbs are wired in parallel, does the brightness of each bulb increase, decrease, or remain the same relative to the brightness of the bulb in the single-bulb circuit? Calculations: Determine the power delivered to a single bulb when the circuit contains (a) only one bulb, (b) two bulbs in series and (c) two bulbs in parallel. Assume that the battery has no internal resistance.