Question

Which of these is the same in parallel branches of a parallel circuit?
a. current is the same
b. voltage is the same
c. resistance is the same
d. all of these

Answer 1

ANSWER - Voltage (or Potential difference to be more precise) remains the same in all the parallel branches of a parallel circuit.

REASON- The voltage doesn't split, the current does. Think of a river that splits up in two directions. The water is moving just as fast in each direction, but there's only half as much water in each branch. Now, apply that to your circuit, where the speed of the water is the voltage and the volume of water is the current. Now, imagine that these two river branches end up in the same stagnant lake, where the flow slows to a stop. Again, there is the same amount of water entering the lake, but it has more kinetic energy left (this is voltage). So, before the resistors, there is energy and after there is none, but, since electrons are flowing, there is current. The current is divided between the two resistors but the voltage drop is identical (since the circuit is only a source and these two resistors, then all of the voltage is dropped through them). So, let's say we have a 10V supply, and two 10ohm resistors. Since each of them will see 10V across them, they each will permit 1A of current, meaning that the power supply will source 2A total.