A flashlight with a resistance RF requires 4 V to operate normally, but only a 12 V source is available. What value of resistor connected in series with the flashlight should be used before the series combination is connected to the source? Note: The value of the resistor is k times RF. What is k?

A flashlight with a resistance RF requires 4 V to operate normally, but only a 12 V source is available. What value of resistor connected in series with the flashlight should be used before the series combination is connected to the source? Note: The value of the resistor is k times RF. What is k?

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter29: Direct Current (dc) Circuits

Section: Chapter Questions

Problem 64PQ: Ralph has three resistors, R1, R2, and R3, connected in series. When connected to an ideal emf...

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Question

A flashlight with a resistance R_F requires 4 V to operate normally, but only a 12 V source is available. What value of resistor connected in series with the flashlight should be used before the series combination is connected to the source? Note: The value of the resistor is k times R_F. What is k?

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