In series combination the current passing through each resistor is:

Correct option is A

• In a series combination of resistors, the same current flows through all the resistors. This is because in a series circuit, the current has only one path to flow through, so the current passing through each resistor is identical.

• (b) Proportional to their thickness: The current is not directly proportional to the thickness of the resistors in a series circuit. The current is the same through each resistor, regardless of their physical dimensions.
• (c) Proportional to their resistance: While the voltage across each resistor is proportional to its resistance, the current passing through all resistors in a series combination is equal.
• (d) Increases gradually: The current in a series circuit does not increase gradually; it remains constant throughout the circuit.