# Session 2- E Field and Dipoles

```Electrostatics 2: E field, and
Dipoles
Supplemental Instruction
Iowa State University
Course:
Instructor:
Date:
Garrett Schieber
Phys 222
Dr. Al-Saqer
9/4/14
Activity 1:
Figure 1: Uniform electric Field.
1) If a particle travels from point p2 to point p1 what must its charge be?
a) Positive
b) Negative
2) If E=120 N/C, m = 2.3 g, the distance from p1 to p2 is x=3cm, and the charged particle starts
at p2 with no initial velocity and takes t=0.6s to reach p1 what is its charge.
(hint: x=xo+vo*t+0.5*a*t2)
a) 2.03 μC
b) -3.19 μC
c) 8.68 μC
d) -5.27 μC
Supplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu
Activity 2:
1) Which way is the initial rotation of the dipole shown above?
a) Positive
b) Negative
2) Draw the Free body diagram of the dipole
3) What is the equation for torque of a dipole?
4) Find the net torque if E=120 N/C, Q = +-5 C, the distance in-between is d=1cm.
5) What is the potential energy at the current orientation?
6) Draw position that would equate to maximum potential energy.
```