Given the resistances \( R_1 = 30 \, \Omega \), \( R_2 = 28 \, \Omega \), the output voltage \( V_o = 84 \, \text{V} \), and the current \( I = 3 \, \text{A} \), we need to determine the node voltage \( V_1 \).
Step 2: Apply Ohm's Law to Find Voltage Drops
Using Ohm's Law, \( V = IR \), we can find the voltage drops across each resistor.
The node voltage \( V_1 \) is the voltage at the node between \( R_1 \) and \( R_2 \). Since \( V_o \) is given as 84 V and \( V_{R2} \) is also 84 V, the voltage at the node \( V_1 \) must be the same as \( V_{R2} \).