energy and voltage in circuits

define series circuit

components are connected one after the other

same amount of current flows through each component

if one component breaks the whole circuit breaks

define parallel circuit

components that are connected on different branches

voltage is same

if one component breaks the others can still work

what is the trend between voltage and current

directly proportional (if voltage increases that means the current increases)

what is the formula for current

voltage / resistance.

what is the current and voltage characteristic for wires

current is directly proportional to the voltage

what is the current and voltage characteristic for resistors

current is directly proportional to voltage if the temperature is constant.

what is the current and voltage characteristic for diode

there is no current until the voltage is 0.6 or above.

what is the current and voltage characteristic for metal filament lamp

the temerpature increases the resistance increases making the current change (that’s why there is a curve)

how would you investigate the current-voltage characteristic

use variable resistor (changes the voltage)

voltemeter (measures voltage)

ammeter (measures the current)

use them in a circuit, ammeter in the series and voltmeter In the parallel circuit. and the variable resistor in the series. And component that you are testing in series. Then measure the readings.

if resistance is higher what does that mean for the current

current would decrease

define LDR

(light dependant resistor)

when light shows = lower resistance = more current

when light doesnt show = more resistance = lower current

used in street lights

define thermoister

a resistor that decreases or increases based on temperature.

when at higher temperature = lower resistance = more current

when at lower temerpature = higher resistance = lower current

used in thermostats

how would you know if current Is present in a circuit

When a filament Lamp or LED lights up, it shows that current is flowing throughout the circuit and also shows that it is complete.

what is the ohms law

if resistance increases, the current and voltage will decrease.

what is the formula for ohms law

V = I x R

V = voltage

I = Current

R = resistance

what is current the rate of

charge, current shows you how much charge passes at a point per second.

what is the formula for charge

charge = current x time

what happens to the current when it goes through a metal wire

the current gets carried by the negatively charged electrons

what happens to the current when it meets a junction (when a wire splits into two)

current is conserved, meaning you cannot lose or create current. So if a wire has 5A and it splits into two, one wire might be 3A and the other might be 2A. In total it will be 5A

is the voltage in each branch of a parallel circuit the same or different from the voltage supply

the voltage in each branch is the same from the voltage supply in a parallel circuit.

For example if the voltage supply is 6V, each branch will receive 6V

define voltage

voltage is the amount of energy transferred of a charge as it moves through a component.

since voltage = energy of charge

1V = 1J per C

what is the formula for energy transferred

E = Q X V

E= energy transferred

Q= charge

v = voltage