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Electric Fields

1. A point charge q produces an electric field of magnitude 90.5 N/C at a distance of 1.68 m. If the field is directed towards the charge, what is the value of q?

2. When the plates of a radio capacitor are charged with 0.18 mC, the potential between them is 9.0 V. What is the capacitance?

3. A pair of parallel plates is separated by 1.0 mm of air. If the plates are charged to a potential difference of 75 V, what is the electric field between the plates?

4. A 40 W electric lamp draws a current of 0.33 A when operated with a potential difference of 120 V. What is the resistance of the lamp?

5. An 1100 W iron, 1200 W frying pan, and a lamp are all connected to a 120 V household circuit fuse for 20 A. What is the maximum wattage lamp that can be used simultaneously with the iron and the frying pan?

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E = 9*10^9*q/r^2
=> 9*10^9*q/1.68^2 = 90.5
=> q = 2.84*10^(-8) C
Because, field is directed towards the charge, therefore, charge should be ...

Solution Summary

The solution includes step-by-step calculations for various problems related to electricity and electric fields. Included are calculations for point charge, capacitance, electric fields, resistance, and wattage.