Electricity

Question 1

define conventional current

Answer 1

• the flow of positive charge
• from the positive terminal
• through an external circuit
• to negative terminal

Question 2

electron flow

Answer 2

• flow of electrons
• from the negative terminal
• through external circuit
• to positive terminal

Question 3

EMF

Answer 3

• total energy supplied per coulomb of charge by the cell

- the potential energy difference across a battery

Question 4

current

Answer 4

amount of charge passing a point in a circuit every second

Question 5

resistivity

Answer 5

• resistance of a 1m length wire

- cross section area of 1m^2

Question 6

resistance

Answer 6

material’s opposition to the flow of the electric current

Question 7

electrical work

Answer 7

work done on a charged particle by an electric field

Question 8

electric power

Answer 8

the rate at which energy is transferred
or
the rate at which work is done

Question 9

equation for current

Answer 9

I = q / t

measured in A

Question 10

ammeter set up

Answer 10

• connected in series with the component in question

- zero resistance, doesn’t affect the current

Question 11

1 A =

Answer 11

1 C/s

Question 12

Potential difference

Answer 12

work done per unit positive charge
or
the amount of gained/transformed energy

Question 13

what’s a Diode?

Answer 13

An electrical component with 2 terminals, only allows the flow of a current in one direction only

reverse bias - negative to positive

Question 14

Series circuit

Answer 14

a path where the whole current flows through each component in a closed loop

Question 15

Parallel circuit

Answer 15

has branches into separate closed loops, dividing the current flow into each pathway

Question 16

Combination circuit

Answer 16

has a combination of series and parallel connections.

Question 17

Kirchhoff’s Law of Voltage

Answer 17

Around any closed loop, the sum of the voltage drops is equal to the EMF

Question 18

Kirchhoff’s Law of Current

Answer 18

the sum of the flowing into any point equals to the sum of the current flowing out from the point

Question 19

Resistors in parallel

Answer 19

the greater the number of resistors, the lower the resistance of the parallel arrangement

the resistance of the resistors in parallel is always less than the smallest resistance in the combination

1/R = 1/R1 + 1/R2

Question 20

Resistors in series

Answer 20

the greater the number of resistors, the greater the resistance of the circuit

Question 21

what is electrical work?

Answer 21

work done on a charged object by an electric field (J)

Question 22

electrical power?

Answer 22

the rate at which work is done/ energy is transferred (J/s)

Question 23

Law of conservation of charge?

Answer 23

the net charge of an isolated system remains constant.