Parallel resistors are connected to each other on both ends. When you connect a fixed voltage across them, then they will all pass current as if the other ones don’t exist.
The amount of current that passes through each parallel resistor can be calculated with Ohms law. The 2 points (nodes) where the resistor terminals connect together on each end will pass all of the current that flows through every parallel resistor.
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10V across a 1,000 ohm resistor will pass about 10mA of current. 10V/1,000Ω = 0.01A (10mA). That’s a good resistance to protect an LED from a 12V power source when using a 1/4W resistor. A lower value 1/4W resistor will probably get too hot. Remember that red indicator LEDs drop about 2V from the current setting resistor(s).
If you want 20mA (indicator LED max. recommended current) of current through the LED, then you can simply add another 1k (1,000Ω) resistor in parallel with the 1k resistor. They will both pass 10mA of current for a total of 20mA.
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