Which of the following quantities remain the same in all parts of a series circuit?

The correct answer is current.

In a series circuit, the current is the same in all parts of the circuit. This is because the current is the flow of electrons, and electrons can only flow through one path at a time. The voltage and resistance in a series circuit can vary, but the current will always be the same.

Voltage is the difference in electrical potential between two points. It is measured in volts (V). The voltage in a series circuit is equal to the sum of the voltages across each component in the circuit.

Resistance is the opposition to the flow of current. It is measured in ohms (Ω). The resistance in a series circuit is equal to the sum of the resistances of each component in the circuit.

Power is the rate at which energy is converted from one form to another. It is measured in watts (W). The power in a series circuit is equal to the product of the voltage and the current.

In a series circuit, the current is the same in all parts of the circuit. This is because the current is the flow of electrons, and electrons can only flow through one path at a time. The voltage and resistance in a series circuit can vary, but the current will always be the same.