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Multiple Choice
A very long insulating cylinder has radius . Every length of the cylinder contains a charge of evenly distributed throughout. What is the strength of the electric field from the axis of the cylinder?
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Verified step by step guidance
1
Identify that the problem involves a long insulating cylinder with a uniform charge distribution, which suggests using Gauss's Law to find the electric field.
Recognize that the electric field inside a uniformly charged cylinder can be found using a Gaussian surface, which is a cylindrical surface co-axial with the charged cylinder.
Apply Gauss's Law, which states that the electric flux through a closed surface is equal to the charge enclosed divided by the permittivity of free space: \( \Phi_E = \frac{Q_{enc}}{\varepsilon_0} \).
Calculate the charge enclosed by the Gaussian surface. Since the charge is uniformly distributed, use the linear charge density \( \lambda = \frac{Q}{L} \), where \( Q = 86 \text{ nC} \) and \( L = 3.0 \text{ m} \).
Use the symmetry of the problem to express the electric field \( E \) as \( E = \frac{\lambda}{2\pi\varepsilon_0 r} \), where \( r = 3.0 \text{ cm} \) is the distance from the axis of the cylinder to the point where the electric field is being calculated.