Checking if Drawing is Correct: Charge Enclosed & Radius

Thread starter jisbon
Start date Jan 30, 2020
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Charge Drawing Radius

In summary, to determine the charge enclosed in a drawing, you must identify the closed surface or boundary of the system and use the equation Q = ∫∫∫ ρdV to calculate the total charge. When checking for mistakes, be sure to include all charges within the boundary and use the correct units and dimensions. To determine the radius, measure the distance on the drawing or use the equation r = √(x^2 + y^2 + z^2). Common mistakes when checking the radius include using inconsistent units and not considering the direction of the radius. Other methods to check the accuracy of the drawing include using Gauss's Law and calculating the electric potential at different points. It is important to use a combination of

Jan 30, 2020

jisbon

Homework Statement: A solid conducting sphere of radius 2 cm has a charge of -10 mC. Concentric With
the sphere is a conducting spherical shell with an inner radius of 4 cm, an outer
radius of 6 cm, and a charge of +5 mC.
(i) Determine the net charge enclosed by a concentric spherical Gaussian surface
when its radius is 1 cm, 3 cm, 5 cm and 7 cm. Explain your answers.
(ii) Find the magnitude and direction of the electric field measured at a point of
radial distance 7 cm away from the centre of the solid conducting sphere.

Relevant Equations: -

Firstly, I would like to check if I drew the diagram correctly:

I'm unsure of the question's phrasing in this case.
Should if the drawing is correct,
(i)
When radius is 1cm, charge enclosed = -10mC

When radius is 3cm, charge enclosed is -10+10 +5? I'm unsure where the 5mC is here in this case.
Thanks.

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Jan 30, 2020

archaic

The spherical shell has a charge of 5mC.

1. How do you determine the charge enclosed in a drawing?

The charge enclosed in a drawing can be determined by looking at the number and type of charges present within the enclosed area. For example, if there are more positive charges than negative charges in the enclosed area, the charge enclosed will be positive. If there are equal numbers of positive and negative charges, the charge enclosed will be zero.

2. What is the significance of the radius in checking if a drawing is correct?

The radius is an important factor in determining the accuracy of a drawing. It represents the distance between the point of interest and the center of the enclosed area. If the radius is incorrect, it can lead to incorrect calculations and conclusions about the charge enclosed.

3. Can the charge enclosed be negative?

Yes, the charge enclosed can be negative. This occurs when there are more negative charges than positive charges within the enclosed area. It is important to take into account the signs of the charges when determining the charge enclosed.

4. How do you check if the drawing is correct based on the charge enclosed and radius?

To check if the drawing is correct, you can use the equation Q = kQ/r, where Q is the charge enclosed, k is the Coulomb's constant, and r is the radius. Plug in the values from the drawing and see if the equation holds true. If it does, then the drawing is correct.

5. What are some common mistakes to avoid when checking if a drawing is correct?

One common mistake is forgetting to take into account the signs of the charges. Another mistake is using the wrong units for the radius, as it should be in meters for the equation to be accurate. It is also important to double check all calculations and make sure they are done correctly.