A voltage divider is a simple circuit that turns a large voltage into a smaller one using two series resistors. The output voltage can be calculated using the formula V_out = V_in * (R2 / (R1 + R2)), where V_in is the input voltage, and R1 and R2 are the resistances of the two resistors.
In a series circuit, the total resistance is simply the sum of all the resistances. The formula is R_total = R1 + R2 + R3 + ... + Rn, where R1, R2, R3, ..., Rn are the resistances of the individual resistors.
In a parallel circuit, the total resistance is found using the reciprocal of the sum of the reciprocals of each individual resistance. The formula is 1/R_total = 1/R1 + 1/R2 + 1/R3 + ... + 1/Rn. After calculating the sum, take the reciprocal to find R_total.
In a series circuit, the current is the same through all components, but the voltage is divided among them. In a parallel circuit, the voltage across each component is the same, but the current is divided among the parallel branches.
The voltage across each resistor in a series circuit can be determined using Ohm's Law, V = I * R, where I is the current through the circuit and R is the resistance of the resistor. Since the current is the same through all resistors in series, you can calculate the voltage drop across each resistor by multiplying the current by the resistance of that resistor.