(a) What is the resistance of a lightbulb that uses an average power of 75.0 W when connected to a 60.0-Hz power source having a maximum voltage of 170 V? (b) What If? What is the resistance of a 100-W lightbulb?
(a)
The resistance of a light bulb.
Answer to Problem 1P
The resistance of a light bulb is
Explanation of Solution
Given Information: Average power of the light bulb is
Formula to calculate the root mean square voltage across the power source is,
Here,
Substitute
Thus, the root mean square voltage across the power source is
Formula to calculate the root mean square current across the power source is,
Here,
Substitute
Thus, the value of the root mean square current across the power source is
Formula to calculate the resistance of a light bulb is,
Here,
Substitute
Thus, the resistance of a light bulb is
Conclusion:
Therefore, the resistance of a light bulb is
(b)
The resistance of a
Answer to Problem 1P
The resistance of a
Explanation of Solution
Given Information: Average power of the light bulb is
Formula to calculate the root mean square current across the power source is,
Here,
Substitute
Thus, the value of the root mean square current across the power source is
Formula to calculate the resistance of a light bulb is,
Substitute
Thus, the resistance of a
Conclusion:
Therefore, the resistance of a
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Chapter 32 Solutions
Physics for Scientists and Engineers with Modern Physics
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