Analyze the provided image and extract all mathematical formulas and text, presenting them in a structured JSON format.

Mathematical Formulas and Text Analysis

• Formula 1: \( I_{общ} = I_1 + I_2 + \dots \)
• Formula 2: \( U_{общ} = U_1 + U_2 + \dots \)
• Formula 3: \( R_{общ} = R_1 + R_2 + \dots \)
• Formula 4: \( \frac{U_1}{U_2} = \frac{R_1}{R_2} \)
• Text: \( \text{параллельные соединения} \)
• Circuit Diagram: A schematic showing multiple resistors in parallel with a voltage source and points labeled 'a' and 'd'. The diagram also includes a symbol representing an ammeter (A).