Finding the magnitude of the eletric field of a uniformly charged rod.

In summary, to determine the magnitude of the electric field along the axis of a uniformly charged rod at a distance of 52.1575 cm from the center, use the Coulomb constant, total charge, and length of the rod to find the linear charge density. Then, take a small element at a distance x from the center and use its charge to find the electric field at the point of interest. Finally, integrate the equation from x = +L/2 to -L/2 to find the total electric field.
  • #1
ILoveCollege
12
0

Homework Statement


"A rod of 13.1 cm long is uniformly charged and has a total charge of -23.2 micro coulombs. Determine the magnitude of the electric field along the axis of the rod at a point 52.1575 cm from the center of the rod. The Coulomb constant is 8.98755e9 N M^2/C^2. Answer in units of N/C"
I'm lost on how to go about solving this. I've tried just doing E=KQ/R^2 with R being 52.1575 cm and I tried E= KQ/(R^2+X^2)^2/3 with X= 52.1575 and R=13.1 but that's wrong to
 
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  • #2
Total charge on the rod is given. Length of the rod L is given. Find the linear charge density λ.Take a small element dx of the rod at a distance x from the center. Charge on this element dq = λ*dx. Let its distance from the point where the electric field is required is (d - x) where d is the distance of the point from he center.
Field due to dq at P is
dE = k*λ*dx/(d-x)^2. Find the integration between the limits x = +L/2 to -L/2
 
  • #3
apparently

I would first clarify the given information and variables in the problem. The length of the rod, 13.1 cm, and the total charge, -23.2 micro coulombs, are given. The distance from the center of the rod to the point where the electric field is being measured, 52.1575 cm, is also given. Additionally, the Coulomb constant, 8.98755e9 N M^2/C^2, is provided.

To solve for the magnitude of the electric field, I would use the formula E = kQ/r^2, where k is the Coulomb constant, Q is the total charge of the rod, and r is the distance from the center of the rod to the point where the electric field is being measured. Plugging in the given values, we get:

E = (8.98755e9 N M^2/C^2)(-23.2 micro coulombs) / (52.1575 cm)^2

Converting the units to meters, we get:

E = (8.98755e9 N M^2/C^2)(-23.2e-6 C) / (0.521575 m)^2

Simplifying, we get:

E = -2.88e4 N/C

Therefore, the magnitude of the electric field along the axis of the rod at a point 52.1575 cm from the center of the rod is 2.88e4 N/C.

If the calculated answer does not match the expected answer, I would double check my calculations and make sure all units are consistent. I would also consider if there are any other factors or assumptions that need to be taken into account, such as the size or shape of the rod. If necessary, I may consult with a colleague or refer to additional resources for assistance.
 

FAQ: Finding the magnitude of the eletric field of a uniformly charged rod.

How is the magnitude of the electric field of a uniformly charged rod calculated?

The magnitude of the electric field of a uniformly charged rod can be calculated using the equation E = k * λ / r, where k is the Coulomb's constant, λ is the linear charge density of the rod, and r is the distance from the rod.

What is the linear charge density of a uniformly charged rod?

The linear charge density of a uniformly charged rod is the amount of charge per unit length along the rod. It is calculated by dividing the total charge of the rod by its length.

How does the magnitude of the electric field change as the distance from the rod increases?

The magnitude of the electric field decreases as the distance from the rod increases. This is because the electric field follows an inverse square law, meaning it decreases with the square of the distance.

Is the magnitude of the electric field the same at all points along the rod?

No, the magnitude of the electric field is not the same at all points along the rod. It is strongest closest to the rod and decreases as the distance increases. It also depends on the linear charge density of the rod.

Can the magnitude of the electric field of a uniformly charged rod be negative?

Yes, the magnitude of the electric field of a uniformly charged rod can be negative. This happens when the direction of the electric field is opposite to the direction of the positive charges on the rod. However, the magnitude itself is always a positive value.

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