Determine the voltage on the outer section of the circuit if the current on it is I = 0.60 A

Determine the voltage on the outer section of the circuit if the current on it is I = 0.60 A, the EMF of the DC source is 10 V, its internal resistance is r = 4.0 Ohm.

According to Ohm’s law for a closed circuit with an EMF, the current strength is determined by the expression:
I = Ε / (R + r), where U is the voltage in the circuit, R is the resistance in the circuit, r is the internal resistance of the source.
Let us express the resistance of the external circuit from this expression:
R = (Ε / I) -r
Substitute the numbers and determine the resistance of the external circuit:
R = (Ε / I) -r = (10 / 0.6) -4 = 12.6 Ohm
Ohm’s law for a section of a chain:
I = U / R
Let us express the voltage from this expression:
U = I * R
Substitute the numbers and determine the voltage of the external circuit:
U = I * R = 0.6 * 12.6 = 7.6 V.
Answer: the voltage of the external circuit is 7.6 V.