Booklet 8: Charge and Current

Question 1

Current- Metals

Answer 1

negatively charged moving electrons
positively charged stationary ions
electron break from atom so it can conduct

Question 2

Current- Solutions (Electrolysis)

Answer 2

the solution is the electrolyte, anode is positive, cathode is negative, anions are negative (because attracted to the positive anode), cations are positive (because attracted to the negative cathode)

Question 3

Electric Current

Answer 3

the rate of flow of charge past a point in a circuit

I=Q/t
current (A) = charge (C) * time (s)

Question 4

Coulomb

Answer 4

the charge which flows past a point in a circuit in a time of 1s when the current is 1A

Question 5

Number density

Answer 5

m^-3
the number of conduction electrons per unit volume

Question 6

Mean Drift Velocity

Answer 6

the average displacement/distance travelled of the electrons along the wire per second; they move slowly in one direction

Question 7

The Speed of Electrons in relation to I=Anev (current, area, number density)

Answer 7

double the current, double the speed- v ∝ I
half the area, double the speed- v ∝ 1/A
smaller number density, increased speed- v ∝ 1/n

Question 8

Kirchhoff’s First Law

Answer 8

the sum of currents entering any point in a circuit is equal to the sum of the currents leaving that same point