Charged Particles and Electric Fields

Question 1

4 characteristics of electric fields

Answer 1

1. Field lines never cross
2. Relative strength represented by density
3. Run parallel to metal surfaces from which they emanate
4. Direction defined as direction of force acting on small positive test charge at that point

Question 2

3 characteristics of field between oppositely charged parallel plates

Answer 2

1. Field lines run parallel to each other (meaning that direction of force in field always same regardless of position (positive with field, negative against))
2. Lines equally spaced (meaning field strength is constant irrespective of charged particle’s position (magnitude of force constant))
3. Potential varies uniformly at rate determined by field strength

Question 3

What happens when force due to electric field is the only force acting on charged particle?

Answer 3

F(net) = F(E)
ma = Eq
a = qE/m

Question 4

What happens when a charged particle placed in an electric field is released?

Answer 4

It accelerates towards oppositely charged plate, EPE is lost and KE is gained (since work done BY field).

Question 5

How do you find final speed on a charged particle released from rest as it moves through V?

Answer 5

Work = ∆E(K)
Fs = ∆E(K)
Eqd = ∆E(K)
qV = ∆E(K)
qV = 1/2mv(f)^2 - 1/2mv(i)^2 <– becomes 0 since released from rest
v(f) = √(2qV/m)

Question 6

If a particle is travelling non-parallel to E-field, what do you do in order to use SUVAT or Work?

Answer 6

Only look at component parallel to field

Question 7

What shape does a charged object projected perpendicular to E-field do?

Answer 7

Makes a parabolic shape

Question 8

What shape does a charged object projected parallel to E-field do?

Answer 8

Makes a linear shape