Electronic components

[jidan]

I know some theory about basic component like resistor, capacitor or transistor diode, inductor and their specification ... I want to start from basic component if i have gone to shop to purchase component what should i say to shopkeeper what should I know before to purchase component
suppose i need 100 ohm resistor can i say give me 100ohm resistor or i need to more specification or i need silicon diode what i say . give idea

 

[ronsimpson]

Do you have a circuit in mind?
We can give you all the right words if we knew that you want to build.
Example: the 100 ohm resistor comes in many sizes. 1/4 watt is a common size. 5% is a common type.

 

[jidan]

Do you have a circuit in mind?
We can give you all the right words if we knew that you want to build.
Example: the 100 ohm resistor comes in many sizes. 1/4 watt is a common size. 5% is a common type.

for example i want make project based on led so I know i need supply led and resistor but actually don't know what value of component i need to purchase

 

[ronsimpson]

Do you want to light one LED?
Where are you going to get power from? Battery what voltage? or adapter (cell phone charger)?

 

[jidan]

Do you want to light one LED?
Where are you going to get power from? Battery what voltage? or adapter (cell phone charger)?

if i have 3v dc cell then how to decide what will the value of led and resistor

 

[BeerBelly]

LEDs require a minimum voltage to work. Different LEDs require different voltages. Most indicator LEDs use between 2 to 3-1/2 volts. The current to drive these LEDs must be limited to keep them from burning out, usually 5 to 30 milli-amps.
Example; 3 volt battery, 2.5 volt 10ma LED
voltage drop(E) current(I) resistor to limit current(R)
Ohm's Law R=E/I
R=.5 / .010
R= 50 ohms
P=(I)squared * R
P=.0001 * 50
P=5 milliwatt

A 1/8 to 1/2 watt resistor should work fine.

 

[jidan]

can

LEDs require a minimum voltage to work. Different LEDs require different voltages. Most indicator LEDs use between 2 to 3-1/2 volts. The current to drive these LEDs must be limited to keep them from burning out, usually 5 to 30 milli-amps.
Example; 3 volt battery, 2.5 volt 10ma LED
voltage drop(E) current(I) resistor to limit current(R)
Ohm's Law R=E/I
R=.5 / .010
R= 50 ohms
P=(I)squared * R
P=.0001 * 50
P=5 milliwatt

A 1/8 to 1/2 watt resistor should work fine.

can I use LDR resistor in place of fix resistor

 

[BeerBelly]

Yes,