Electricity Current Definitions

Question 1

Electric current is: {Definition} & {Formula}

Answer 1

Electric current is: the flow of charge. [A]
I = Q/t
[I = current, Q = charge, t = time]
** It does not appear in the tables so you need to know. **

Question 2

Ohms law is: {Formula}

Answer 2

Ohms law is: at constant temperature,
V/l = constant
[V = Voltage, I = Current]

Question 3

Resistance is: {Formula}

Answer 3

Resistance is:
R = V/I
[R = resistance, V = voltage, l = current]

Question 4

An Ohm is: {Definition}

Answer 4

An Ohm is: there is a resistance of 1 ohm between two points if a potential difference of 1 volt across the points causes a current of 1 amp to floor.

Question 5

Resistivity is: {Formula} & {Definition}

Answer 5

Resistivity is:
P(rho) = RA/L
[P(rho)=resistivity, R=resistance, A=cross sectional area, L=length]
or the resistance of a 1m length of the substance that has a cross-sectional area of 1 m^2.

Question 6

Joule’s Law is: {Formula}

Answer 6

Joule’s Law is:
P x I^2
[P = power, I = current]

Question 7

An electrolyte is: {Definition}

Answer 7

An electrolyte is: a substance that conducts electricity by the movement of ions.

Question 8

Electrolysis is: {Definition}

Answer 8

Electrolysis is: the process of causing a chemical reaction by passing electricity through an electrolyte.

Question 9

Semiconductors are: {Definition}

Answer 9

Semiconductors are: materials with a resistivity between that of an insulator and a conductor.

Question 10

Intrinsic conduction is: {Definition}

Answer 10

Intrinsic conduction is: a conduction through a pure semiconductor.

Question 11

Doping is: {Definition}

Answer 11

Doping is: the adding of a controlled amount of an impurity (e.g., phosphorus) to a semiconductor to improve its conductivity.

Question 12

Extrinsic conduction is: {Definition}

Answer 12

Extrinsic conduction is: conduction through a doped semiconductor.

Question 13

n-type semiconductor contains: {Definition}

Answer 13

n-type semiconductor contains: more electrons than holes as charge carriers, so the electrons are the majority charge carrier. It is silicon doped with phosphorus.

Question 14

p-type semiconductor contains: {Definition}

Answer 14

p-type semiconductor contains: more holes than electrons as charge carriers, so the holes are the majority charge carrier. It is silicon doped with boron.