• 100% Satisfaction Guarantee
akch2002, Engineer
Category: Homework
Satisfied Customers: 3119
Experience:  Home work expert
46493125
akch2002 is online now

# 1. Two spheres, each of mass M=2.33 g, are attached to pieces

1. Two spheres, each of mass M=2.33 g, are attached to pieces of string of length L=45 cm to a common point. The strings initially hang straight down, with the spheres just touching one another. An equal amount of charge, q , is placed on each sphere. The resulting forces on the spheres cause each string to hang at an angle of Ɵ=10 ͦ from the vertical. Determine q, the amount of charge on each sphere.
2. A thin glass rod is bent into a semicircle of radius R. A charge +Q is uniformly distributed along the upper half, and a charge –Q is uniformly distributed along the lower half as shown in the figure. Find the magnitude and direction of the electric field E (in component form) at point P, the center of the semicircle.
http://maxwell.uncc.edu/pleilaba/2102%20Final%20Exam%20Fall%202007%20solutions.pdf

3. A conducting solid sphere of radius 20 cm is located with its center at the origin of a three-dimensional coordinate system. A charge of 0.271 nC is placed on the sphere.
(a) What is the magnitude of the electric field at point (x, y, z)=(23.1 cm, 1.1 cm, 0 cm)?
(b) What is the angle of this electric field with the x-axis at this point ?
(c) What is the magnitude of the electric field at point (x, y, z)=(4.1 cm, 1.1 cm, 0 cm) ?
4. Two parallel plates are held at potentials of +200 V and -100 V. The plates are separated by 1 cm.
(a) Find the electric field between the plates.
(b) An electron is initially placed midway between the plates. Find its kinetic energy when it hits the positive plate.
5. A point charge of +2 μC is located at (2.5 m, 3.2 m). A second point charge of -3.1 μC is located at (-2.1 m, 1 m).
(a) What is the combined electrostatic potential of this two charges at x=20.1 cm , also on the x-axis ?
(b) At which point(s) on the x-axis does this potential have minimum?
6. A 5-nF capacitor charged to 60 V and a 7-nF capacitor charged to 40 V are connected with the negative plate of each connected with the negative plate of the other. What is the final charge on the 7-nF capacitor ?
7. A parallel plate capacitor has a capacitance of 120 pF and a plate area of 100 cm2. The space between the plates is filled with mica whose dielectric constant is 5.4. The plates of the capacitor are kept at 50 V.
(a) What is the strength of the electric field in the mica ?
(b) What is the amount of free charge on the plates ?
(c) What is the amount of charge induced on the mica ?

8. When a 40-V emf device is placed across two resistors in series, a current of 10 A is flowing in each of the resistors. When the same emf device is placed across the same two resistors in parallel, the current through the emf device is 50 A. What is the magnitude of the larger of the two resistors ?
9. A parallel-plate capacitor is charged and then disconnected from a battery. By what factor does the stored energy change ( increase or decrease) when the plate separation is doubled ?
10. A current density of 6x10-13 A/m2 exists in the
atmosphere at a location where the electric field is 100 V/m. Calculate the electric conductivity of the Earth’s atmosphere in this region.
11. A small but measurable current of 1.2x10-10 A exists in a copper wire whose diameter is 2.5 mm. The number of charge carriers per unit volume is 8.49 x1028 m-3. Assuming the current is uniform, calculate (a) the current density and (b) electron drift speed.
12. A 2-kW heater element from a dryer has a length of 80 cm. If a 10 cm section is removed, what power is used by the now shortened element at 120 V ?
Kindly inform time in hours by which you would like to have answers for these questions.
Customer: replied 4 years ago.

Is it possible to get the answers for these in about 8 hours?

Some of the questions are easy and these can be replied quite fast but some questions will require time but still I will try. Whatever I can do fast, I will upload their answers first and I will submit the answers to remaining questions later but by 10pm or so.
Customer: replied 4 years ago.

Oh is it possible to get the answers for at least 10 questions before 3 pm please? Its very urgent for me! I will pay extra for it?

Kindly inform me time in hours as I am in different time zone.
Customer: replied 4 years ago.

oh ok, I mean the maximum time I have left is 11 hours? Is it possible to get the solutions for at least 10 out of the total 12 questions I posted in that amount of time?

Customer: replied 4 years ago.
,I am still waiting on your response?
OK. I will upload answers at least to 10 questions by due time. Thanks.
Customer: replied 4 years ago.

Ok thanks

Welcome
I could solve 11 problems and only typing is left and hope to upload answers much before due time. I will try to solve the remaining problem also.