?

Free Version

Upgrade subject to access all content

Moderate

Displacement From the Center of a Disk of Charge

EANDM-JWFTNX

Figure 1 depicts a thin non-conducting disk of charge of radius $R$, upon which a surface charge density of $\sigma = 38.9 \: \rm \frac{nC}{m^2}$ has been placed.

Figure 1. Timothy Black. Created for Albert.io. Copyright 2016. All rights reserved.

A field point $P$ exists a distance $z$ above the center of disk. Figure 2 shows the electric potential $V$ at the field point as a function of the radius of the disk $R$.

Figure 2. Timothy Black. Created for Albert.io. Copyright 2016. All rights reserved.

What is the displacement $z$ of the field point from the center of the disk?

A

$z = 7.33 \text{ m}$

B

$z = 10.0 \text{ cm}$

C

$z = 3.91 \text{ cm}$

D

$z = 6.67 \text{ cm}$