Imagine a simple circuit with 10V battery and 5 ohms resistor. The current would be 2.0 A in this case. If 20V battery was used with the same setup, the current would double to 4.0A since the resistance doesnt change for a resistor. If this is correct, voltage drop across the resistor would have to be 10V and 20V respectably.

1. Do all the voltage always drop and occurs across a resistor in a simple series circuit? (Does the resistor always take in every potential energy when current goes through a resistor? if so what happens in a series circuit with 2 resistors?)

2. Why is it that all the voltage drops (10V and 20V) when resistor's resistance is the same?

3. Do resistors resist only against current not voltage?

Answer to these desperate questions would be very appreciated

Thanks