P3.2.1 + 2 pd current, series and parallel

Question 1

what is required for current to flow in a circuit

Answer 1

potential difference

Question 2

how is potential difference caused

Answer 2

it’s caused by the separation of charges inside a battery

Question 3

how is potential difference varied

Answer 3

by the way the battery is constructed, NOT by size
it doesn’t work like if battery is bigger, pd is bigger aswell.

Question 4

potential difference is the difference between …

Answer 4

the positive terminal and the negative

Question 5

how do you measure pd

Answer 5

with a voltmeter

Question 6

longer line

Answer 6

positive terminal

Question 7

shorter line

Answer 7

negative terminal

Question 8

what happens when pd is applied between the end of the wire

Answer 8

electric field gets set up, happens very quickly , because of that charged electrons move

Question 9

energy transferred formula

Answer 9

pd x charge

Question 10

what’s units of pd

Answer 10

volts

Question 11

what’s the unit of energy

Answer 11

joules

Question 12

units of charge

Answer 12

C

Question 13

what happens to the current in a series circuit

Answer 13

the current is the same everywhere

Question 14

how is current measured

Answer 14

ammeter

Question 15

what is a difference between an ammeter and a voltmeter

Answer 15

voltmeter has to be connected in parallel to component

Question 16

specifically what do voltmeters do

Answer 16

measuring the drop in potential across the area they are connected

Question 17

what does a voltmeter measure across a battery/cell

Answer 17

measured the rise in potential

Question 18

what does the voltmeter measure across a component

Answer 18

drop in potential

Question 19

Vs = V1 + V2

Answer 19

the reading on the voltmeter across the components will add up to the reading across battery or cell

Question 20

what is the key difference between a series and parallel circuit

Answer 20

in a parallel, the current in all the loops add up to the current near battery

Question 21

how do we know the pd across a component

Answer 21

it will be the same as all the other components and the battery

Question 22

what can you do if a bulb doesn’t light when building circuits

Answer 22

• try another battery
• if doesn’t work, change the bulb
• if that doesn’t work, change the lead
• replace one lead at a time and check which one doesn’t work
• when connecting ammeter, make sure that the ammeter negative terminal is closest to the negative terminal of the battery.

Question 23

why do electrons in the wires of a circuit move

Answer 23

The “electrical pressure” due to the difference in voltage between the positive and negative terminals of a battery causes the charge (electrons) to move from the positive terminal to the negative terminal