Download Electrostatics Review Problems

Name _____________________________________________
Period _____________
Worksheet 146- More Electrostatics Review
Problems
HCP030706C
1. A certain ion has 3 excess electrons. What is this ion’s charge, in Coulombs?
(-4.8 x 10-19 C)
2. How many protons must a compound have if it has 50 electrons and a net charge of
+9.6 * 10-18 C? (110 protons)
3. What is the electrostatic force between two protons in a nucleus if they are separated
by a distance of 8 * 10-18 m? (+3.6 x 106 n)
4. A 6.4 * 10-9 C charge is 4 * 10-4 m away from a -3.2 * 10-12 C charge. How strong is
the attractive force between them? (-1.15 x 10 -3 n)
5. A 2 * 10-10 N force exists between two unknown charges q1 and q2 when they are a
distance R apart. If they are moved twice as far apart, what is the new value of this
force? (5 x 10-11 n)
6. What is the electric field strength a distance of 3 * 10-12 m from a 2-proton helium
nucleus? ( 3.2 x 1014 n/C)
7. If an electron is placed at the location mentioned in #6, what is the attractive force it
will feel? (-5.12 x 10-5 n)
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Electrostatics Review Problems
Name _____________________________________________
Period _____________
8. A 60,000 N/C electric field is detected a distance R from a certain charge q. If the
charge is reduced by half, what is the new strength of the electric field at this point?
(3.0 x 104 n/C)
9. Two parallel plates are charged to a voltage of 3 V. If they are 0.025 m apart, what is
the strength of the electric field between the plates? (120 n/C)
10. What is the electric potential 0.01 m away from a 1.6 * 10-9 C charge? (1,440 v)
11. A parallel plate capacitor is capable of holding 0.005 C of charge when it is at a
voltage of 110 V. What is its capacitance? (4.55 x 10-5 F)
12. A 2 * 10-4 F capacitor is charged with a potential of 12 V. How much charge is held?
(2.4 x 10-3 C)
13. A parallel plate capacitor is formed by taking plates of area 1.6 * 10 -3 m2 that are
separated by a distance of 0.08 m. If no dielectric is used, what is the capacitance?
(1.77 x 10-13 F)
14. If a charge of 8 * 10-10 C is stored on the capacitor from #13, what is the voltage
across the plates? What is the electric field strength inside the plates? (V=4,520 v)
(E= 5.65 x 104 n/C)
15. Now, a slip of wax paper ( = 5.0) is placed between the plates. What are the “new”
answers to #13, 14? (8.85 x 10-13 F) (904 v) (1.13 x 104 n/C)
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Electrostatics Review Problems
Name _____________________________________________
Period _____________
Extra-challenging
For the following problems, consult the picture above. Let R = 1 m.
16. Let Q = 3q. At what distance(s) x on the x-axis is the net electric field equal to zero?
17. Let Q = -3q. At what distance(s) x on the x-axis is the net electrostatic force on a
proton equal to zero?
Physics
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Electrostatics Review Problems