electricity

Question 1

conductor

Answer 1

any substance through which charge can flow

Question 2

insulator

Answer 2

any substance through which electric charge cannot flow

Question 3

coulombs law

Answer 3

the force of attraction or repulsion between two point charges is directly proportional to the product of the charges and inversely proportional to the distance between them

Question 4

electric field

Answer 4

any region of space where static electric charge experiences a forces other than the force of gravity

Question 5

electric field strength

Answer 5

at a point in an electric field is the force per unit charge at that point (E=F/Q)

Question 6

potential difference

Answer 6

between two points in an electric field is the work done in bringing a charge of +1C from one point to the other

Question 7

electric current

Answer 7

the flow of electric charge

Question 8

capacitance

Answer 8

is the ratio of the charge on the conductor to its potential (C=Q/V)

Question 9

size of an electric current

Answer 9

the amount of charge passing any point of that conductor per second

Question 10

ampere

Answer 10

coulomb per second

Question 11

EMF

Answer 11

the voltage when applied to a circuit

Question 12

resistance

Answer 12

the ratio of potential difference across it to the current flowing through it (ohms)

Question 13

joules law

Answer 13

the rate at which heat is produced in a conductor is directly proportional to the square of the current provided its resistance is constant

Question 14

fuse

Answer 14

a piece of wire that will melt when a current of a certain size passes through it

Question 15

MCBS

Answer 15

a bimetallic strip and electromagnet which separate and break the circuit when current is larger than a certain value

Question 16

RCDS

Answer 16

decent the difference between current in the live and neutral wire

Question 17

semiconductor

Answer 17

a substance whose resistance is between that of a good conductor and good insulator (resistance decreases as temperature increases)

Question 18

intrinsic conduction

Answer 18

a pure semiconductor due to electrons moving from negative to positive and an equal number of holes moving in the opposite direction

Question 19

extrinsic conduction

Answer 19

increased conduction in a semiconductor due to addition of impurities

Question 20

doping

Answer 20

adding small controlled impurities to increase conductivity

Question 21

N type semiconductors

Answer 21

are those in which the impurity added produce more electrons

Question 23

depletion layer

Answer 23

the region at both sides of a p-n junction that contains no tree majority charge carriers, is an insulator

Question 24

junction voltage

Answer 24

the potential difference that exists across a p-n junction

Question 25

rectification

Answer 25

the conversion of ac to dc