p3

Question 1

what is current?

Answer 1

the flow of electrical charge measured in amperes

Question 3

what is potential difference

Answer 3

the energy transferred per unit charge measured in volts

Question 4

how do you calculate resistance?

Answer 4

use Ohms law:
v= ir

Question 5

how do series and parallel circuits differ

Answer 5

in series circuits, current is same throughout and voltage DIVIDES

parallel: voltage is same across branches and CURRENT divides

Question 6

how do objects become charged

Answer 6

through friction- electrons can be transferred, causing one object to become negatively charged and the other positively charged

Question 7

describe differences between series and parallel circuits including how current and potential difference behave and where measuring instruments go

Answer 7

series circuit:
one loop
current is the same everywhere in the circuit
voltage is shared across components
a break anywhere stops the whole circuit

parallel circuit:
multiple loops or branches
pd is the same across EACH BRANCH
current splits between branches, depending on resistance

ammeter series
voltmeter in parallel

Question 8

direction of current

Answer 8

positive to negative terminal of power supply (convention current)

Question 9

resistance

Answer 9

how much a material resists the flow of current
ohms

Question 10

for which components does resistance stay same

Answer 10

constant:
fixed resistor, wire- obeys Ohms law

changing;
filament lamp- resistance increases as current heats the filament
diode- only allows current in one direction, has high resistance the other way
thermistor= resistance deceases as temp increases
LDR- resistance decreases as light increases

Question 11

linear grah examples

Answer 11

wire
fixed resistor

Question 12

non linear graph examples

Answer 12

filament lamp
diode
thermistor
LDR

Question 13

why does total resistance increase in series but decrease in parallel

Answer 13

in series

electrons have to pass thru each resistor one after th either
makes total resistance increase

in parallel

electrons have more than one path to take
makes it easier for current to flow
total resistance is less than the smallest resistor in the circuit

Question 14

design a circuit to test components or measure current and energy transfer over time

Answer 14

use power supply ammeter and voltmeter
connect component
measure voltage and current
use v=ir
q=it
e=qv