1. Electric Field (Continued)
E-Field w3d3
Electric Field (Continued)

2. Happnins Today Quiz 2 Continue with E-Field A problem or two Monday
7:30 am PROBLEM SESSION
Electric Flux and Gauss’s Law
Wednesday
Start Unit on Potential
Sunday
WebAssign Due
Friday
Quiz, Etc.

3. The Coulomb force Coulombs Law applies:
The FORCE is always on a particular charge
The Force on a particular charge under the influence of other charges is found by SUPERPOSITION. (Add em up!!)
The force is a VECTOR!!! You add them as vectors!
A charge cannot apply a force to itself.

4. Two Charges

5. Electric Field
If a charge Q is in an electric field E then it will experience a force F.
The Electric Field is defined as the force per unit charge at the point.
Electric fields are caused by charges and consequently we can use Coulombs law to calculate it.
For multiple charges, add the fields as VECTORS.

6. It can’t be calculated without additional information.
An electric field of 10 N/C exists at a point in space. A 5.0 Coulomb charge is placed at the point. The force on the charge is
It can’t be calculated without additional information.
5.0 N
10.0 N
50.0 N
2.6 Tharks

7. Superposition and Symmetry
What is the electric field at the center of the square array?
Superposition and Symmetry

8. Which one of the following statements is true concerning the magnitude of the electric field at a point in space?
A) It is a measure of the total charge on the object. B) It is a measure of the electric force on any charged object. C) It is a measure of the ratio of the charge on an object to its mass. D) It is a measure of the electric force per unit mass on a test charge. E) It is a measure of the electric force per unit charge on a test charge.

9. At which point (or points) is the electric field zero N/C for the two point charges shown on the x axis?
A) The electric field is never zero in the vicinity of these charges.
B) The electric field is zero somewhere on the x axis to the left of the +4q charge.
C) The electric field is zero somewhere on the x axis to the right of the –2q charge.
D) The electric field is zero somewhere on the x axis between the two charges, but this point is nearer to the –2q charge.
E) The electric field is zero at two points along the x axis; one such point is to the right of the –2q charge and the other is to the left of the +4q charge.

11. THEN BACK TO UNIT 3 – THE ELECTRIC FIELD.
Let’s Do The QUIZ!
THEN BACK TO UNIT 3 – THE ELECTRIC FIELD.
TRY TO FINISH IT TODAY.