Chapter 22 electric fields

Question 1

What is an electric field?

Answer 1

A region in which charged objects experience a force

Question 2

What is the formula for electric field strength?

Answer 2

E = F/Q

Question 3

What is formula for force exerted on charged objects?

Answer 3

F =Qq/4pir^2 epsilon

Question 4

What is the formula for electric field strength in a radial field and how do you derive it?

Answer 4

Substitue force formula into electric field strength formula to remove little q from the force formula

Question 5

Differences between gravitational fields and electric fields?

Answer 5

One is created by mass, one is created by charge
GF is always attractive, EF is repulsive for positive and attractive for negative

Question 6

Electric field strength between parallel plates

Answer 6

A charge between two parallel plates that are oppositelt charged experiences a force and moves to the plate
W = Fd
The force is provided by the electric field, EQ = F
VQ = EQd
E = V / d

Question 7

Capacitance relation to Area and distance of plates

Answer 7

C = Aε/d
ε = ε_rε₀

Question 8

Electircal potential energy

Answer 8

Area under a force distance graph
= Force formula between two point charges x R
The energy required to bring a test charge from infinity to that point
E = Qq / 4 pi r ε₀

Question 9

Electric potential with units

Answer 9

The energy required per unit charge to bring a test charge from that infinity to that point
V = Q / 4 pi r ε₀
Units is volts because E/q = V (electric work done)

Question 10

Capacitance of an isolated sphere

Answer 10

C = Q/ V
rearranged electirc potential for Q
C = V4 pi r ε₀ / V
C = 4 pi r ε₀