Which statement is true? a) voltage varies throughout a series circuit. b) voltage remains the same throughout a series circuit.

Correct Answer is A

In a series circuit, the voltage across each resistive element is different and depends on the resistance of that element. However, the current throughout the series circuit is the same.

In a parallel circuit, the voltage is same across all the branches however the current in each branch is different and depends on the resistance of that branch. 

Points to Remember:
1) In series circuit current remains the same and voltage varies
2) In parallel circuit voltage remains the same and current varies