Paper 1, Topic 7 - Electric and Magnetic Fields

Question 1

What is an electric field?

Answer 1

A region in which charged particles experience a non-contact force.

Question 2

What is coulomb’s law?

Answer 2

The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distances between them.

Question 3

What is the equation for coulombs law?

Answer 3

F = KQq / r²

Question 4

What are 3 equations used to determine electric field strength?

Answer 4

E = F / Q E = KQ / r² E = V / d

Question 5

What is the definition of electric potential?

Answer 5

The amount of work done in moving a unit positive point charge from infinity to that point

Question 6

What is the definition of electric potential difference?

Answer 6

The work done moving a positive charge from one point to another.

Question 7

What is the equation for electric potential difference?

Answer 7

ΔW = Q x ΔV

Question 8

What is the definition of capacitance?

Answer 8

The amount of charge it can store per unit of potential difference, measured in Farads.

Question 9

What is the equation for capacitance?

Answer 9

C = Q / V

Question 10

What are three equations used to work out the energy stored in a capacitor?

Answer 10

E = ½ x Q x V   
E = ½  x C x V²
E = Q² / C

Question 11

What is the definition of time constant when talking about capacitors?

Answer 11

The time taken to charge the capacitor to 63% of its final value.
And the time taken to discharge the capacitor to 37% of its initial value.