How Do You Calculate the Electric Field of a Dipole at a Specific Point?

AI Thread Summary
To calculate the electric field of a dipole at a specific point, the formula used is E = 2qs/(4πE * r^3), where E is the permittivity of vacuum. Given the dipole with charges of +4 nC and -4 nC separated by 2 mm, and evaluated at a point 5 cm away, the initial calculation yielded 2.88 N/C. The user identified an error in their computation, specifically neglecting to cube the distance d in the formula. Additionally, it was noted that the electric field perpendicular to the dipole is half of that on the axis, suggesting a value of 1.44 N/C for the perpendicular field. The discussion highlights the importance of careful unit conversion and adherence to the formula's requirements.
Squall
Messages
53
Reaction score
0

Homework Statement


A dipole consists of two charges +q and -q, held apart by a rod of length s, as shown in the diagram. If q = 4 nC and s = 2 mm, what is the magnitude of the electric field due to the dipole at location A, a distance d = 5 cm from the dipole?

The diagram shows point A being on axis with the dipole.

Homework Equations



The formula for on axis is 2qs/4piE*r^3, where E is the permittivity of vacuum

The Attempt at a Solution



So to solve this first I converted all units

q = 4nC = 4e-9C
s = 2mm = .002m
d = 5cm = .05m

Then I plug in the values into the formula

2*4e-9C*.002m/4pi*8.85e-12*.05m = 2.88N/C
But that seems to be the wrong answer can someone please tell me what I'm doing wrong
and also is it true that the field perpendicular to the dipole is just half of what it would be if it was on axis. If that's true than the field 5cm perpendicular to the dipole should be just half of what I come up with, in this case 1.44N/C.

Thank You for your help
 
Physics news on Phys.org
Oh I think I figured out where I went wrong I forgot to cube d,
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is（Figure 2）： F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Magnitude of an Electric Field due to a dipole
Replies
6
Views
2K
Expression for Magnitude of Electric Field by dipole integral
Replies
4
Views
2K
Calculating Torque and Work of an Electric Dipole in a Uniform External Field
Replies
11
Views
2K
Potential Difference between Two Points affected by a Dipole
Replies
6
Views
4K
How do I calculate the potential created by a dipole
Replies
2
Views
2K
Electric Field Calculations for Stationary Charges and a Dipole at Point P(0,4m)
Replies
1
Views
1K
How Is the Electric Field Calculated for a Point Outside a Charged Ring?
Replies
11
Views
3K
Time period of small oscillations of the point dipole
2
Replies
52
Views
5K
Calculating Electric Field due to a Dipole
Replies
1
Views
8K
Electric dipole in uniform electric field
Replies
7
Views
5K

Hot Threads

Recent Insights

Back
Top