Electric Fields

Question 1

What’s an electric field?

Answer 1

Region or space where an object experiences a non-contact force due to being charged

Question 2

Electric field strength?

Answer 2

The force done per unit of charge
E = F/Q

Question 3

What’s an equipotential?

Answer 3

A line of constant electric potential.

Question 4

What’s the relationship between equipotential and radius (distance)?

Answer 4

The further away the field strength decreases.

Question 5

What’s the formula for the field strength between 2 parallel plates?

Answer 5

E = V /d
E is field strength
V is p.d
d distance

Question 6

What’s coulomb’s law?

Answer 6

It gives the attractive or repulse force between 2 point charges in a vacuum.

Question 7

Coulomb’s law formula?

Answer 7

F = Q(1)*Q(2) / 4πε(0)r²

So F ∝ 1/ r²

Question 8

ε(0) value

Answer 8

8.85x10-¹²

Question 9

What’s the relationship between Q(1) and Q(2)

Answer 9

Always equal and opposite depending on the charge

Question 10

Point charge?

Answer 10

Charge being concentrated at 1 point and has a radial field

Question 11

Electric Potential?

Answer 11

The potential energy that a unit of charge (+1C) would have at a point

Question 12

Electric Potential formula?

Answer 12

V = Q/4πε⁰r

Question 13

Capacitors?

Answer 13

Electrical component that stores charge

Question 14

What are capacitors made of?

Answer 14

2 conductive plates separated by air or an insulator

Question 15

How do capacitors work?

Answer 15

When connected to a power source, a negative and positive charge is stored on each side and stopped by the insulator.
This causes a p.d leading to uniform electric field.

Question 16

Capacitance formula?

Answer 16

C = Q/V

Question 17

Formula for energy stored in a capacitor?

Answer 17

W = QV/2
W=CV²/2
W=Q²/2C

Question 18

What effects the time taken to charge?

Answer 18

Capacitance and the resistance

Question 19

In what way do capacitors discharge?

Answer 19

Exponentially
Q= Q(0)e^(-t/RC)
Or
Q = Q(0)e^(-t/τ)

Question 20

What is the time constant (τ)

Answer 20

Time taken for 1/e of Q to discharge
τ=RC

Question 21

What is an exponential curve?

Answer 21

A constant fractional change in a given time interval

Question 22

What’s a uniform electric field and how can it be produced?

Answer 22

Parallel electric field lines that are always the same distance apart.
Produced when you put two parallel plates on the opposite poles of a battery

Question 23

How are lines of equipotential shown from a point charge?

Answer 23

Circles with increasing distance away from the point charge

Question 24

What is equipotential for a radial field?

Answer 24

Shows the points that are equally distanced apart.