which is the primary purpose of a resistor in series with a led being driven by a flip-flop
a. Limit voltage
b. Limit current
c. Limit speed
d. Limit power
b. Limit current.
The primary purpose of a resistor in series with a LED being driven by a flip-flop is to limit current.
Explanation:
When a LED is connected to a voltage source without any resistance, the current flowing through the LED can become too high, leading to the LED being damaged or burnt out. By adding a resistor in series with the LED, we can control and limit the amount of current flowing through the circuit.
To calculate the resistance value needed to limit the current, we use Ohm's Law, which states that the current flowing through a circuit is equal to the voltage across the circuit divided by the resistance. Given the desired current value and the forward voltage drop of the LED, we can determine the appropriate resistor value using this formula:
Resistance (R) = Voltage (V) / Current (I)
In this case, the resistor is used with a flip-flop, which is a digital circuit component used for storing and controlling binary data. The flip-flop provides the voltage source for the LED. By adding a resistor in series, it ensures that the LED operates within its specified current rating, protecting it from excessive current flow and preventing damage. Therefore, the correct answer is option b - limit current.