A galvanic cell with an EMF of 1.5V and an internal resistance of 1 0m is closed to an external resistance of 4 Ohm. Find the current in the circuit, the voltage drop in the internal part of the circuit, and the voltage at the terminals of the element.
To determine the current in the circuit, we use Ohm’s law for a complete electrical circuit:
I = E / (R + r),
where E is the electromotive force, R is the external resistance of the circuit, r is the internal resistance of the EMF source, I is the current;.
Let’s calculate the current:
I = E / (R + r) = 1.5 / (4 + 1) = 1.5 / 5 = 0.3 (A).
The voltage drop in the inner part of the circuit is determined from the formula:
Ur = I * r.
Substituting the numerical values of the current strength and internal resistance, we get:
Ur = I * r = 0.3 * 1 = 0.3 (B).
The voltage drop across the terminals is determined from the formula:
UR = I * R.
Substituting the numerical values of the current strength and external resistance, we get:
UR = I * R = 0.3 * 4 = 1, 2 (B).
Answer: I = 0.5 (A), Ur = 0.3 (B), UR = 1.2 (B).