bonsoir, je peux vous aider avec les maths laissez-moi comprendre merci
Answer:
a. E = 122.4 N/C
b. E = 58.2 N/C
c. E = 0
Explanation:
The electric field at an arbitrary point away from the axis of the cylinder can found by applying Gauss’ Law, which states that an electric flux through a closed surface is equal to the total charge enclosed by this surface divided by electric permittivity.
In order to apply this law, we have to draw an imaginary cylindrical surface of arbitrary height ‘h’ and radius ‘r’, which is equal to the point where the E-field is asked.
A. For the outside of the cylinder, we will draw our imaginary surface with r = 1.97.

B. This time our imaginary surface should be inside the cylinder, therefore the enclosed charge will be less than that of part A.

C. In this case our imaginary surface will be inside the cylinder, where there is no charge at all. Therefore, the enclosed charge will be zero and the electric field will be zero.
I believe the answer is node, but I'm not totally sure.
I believe the answer is 25*3.5 I apologize if this information is incorrect.<span />
The difference between the two numbers is 31.
I didn’t quite understand your question, perhaps typos?