I = 3 a R = 15 Ом r = 0,1 Ом E- ？

To find the electromotive force (E) in the circuit, we can use Ohm's law and the concept of total resistance in the circuit. Based on the given values:

• Current \( I = 3 \) A
• Resistance \( R = 15 \) Ω (load resistance)
• Internal resistance \( r = 0.1 \) Ω (internal resistance of the source)

The total resistance \( R_{\text{total}} \) in the circuit is the sum of the load resistance \( R \) and the internal resistance \( r \):

\[ R_{\text{total}} = R + r = 15 \, \Omega + 0.1 \, \Omega = 15.1 \, \Omega \]

Now, according to Ohm's law, the voltage (or electromotive force, \( E \)) can be calculated using the formula:

\[ E = I \times R_{\text{total}} \]

Substituting the known values:

\[ E = 3 \, A \times 15.1 \, \Omega = 45.3 \, V \]

Thus, the electromotive force \( E \) is:

\[ E = 45.3 \, V \]