Four resistors of 1 Ohm each are connected in series and connected to a current source
Four resistors of 1 Ohm each are connected in series and connected to a current source, EMF of which is 4.5 V and an internal resistance of 0.5 Ohm. Find the voltage across one resistor.
R1 = R2 = R3 = R4 = 1 ohm.
EMF = 4.5 V.
r = 0.5 ohm.
U1 -?
When connecting the conductors in series:
the voltage at the terminals of the current source will be the sum of the voltages at each resistance U = U1 + U2 + U3 + U4;
the current in the circuit and in each conductor is the same I = I1 = I2 = I3 = I4;
the resistance of the entire circuit is the sum of all resistances R = R1 + R2 + R3 + R4.
We express the current in the circuit I according to Ohm’s law for a closed loop: I = EMF / (R + r).
R = 4 * R1.
I = 4.5 V / (4 * 1 Ohm + 0.5 Ohm) = 1 A.
We find the voltage across the resistor according to Ohm’s law for a section of the circuit: U1 = I1 * R1 = I * R1.
U1 = 1 A * 1 Ohm = 1 V.
Answer: the voltage across the resistors is U1 = U2 = U3 = U4 = 1 V.