bluejay wrote:andrewwski wrote:bluejay wrote:I have a little problem with voltage drops. How do you find it out?
That depends on the circuit and the component. But generally a combination of Ohm's Law or Kirchoff's Laws.
so..what if a problem states that a 4.0 ohm resistor, a 8.0 ohm resistor, and a 10.0 ohm resistor are connected in series across an 11-V battery, what is the total volatage drop across the 4.0 ohm and 8.0 ohm resistors? and how do you find it out?
One method would be to replace all three resistors with a single 22.0 ohm resistor. Applying Ohm's law, you know that there is a 0.50 ampere current across the resistor. Since there are not any nodes in the middle, KCL tells you that this 0.50 ampere current will flow through all three resistors. You can then apply Ohm's law again to calculate that across the 12.0 ohm equivalent resistor (4.0 and 8.0), V=0.50*12.0 ohms would be 6.0 volts. You could also solve it as a voltage divider between the 12.0 equivalent and the 10.0 ohm resistor to get the same answer.