DP 4.1 (50 points) In the portion of the circuit shown, calculate the potential difference 30 between points a and b. b 30 W I-ZOA DP 4.2 (50 points) Consider the circuit diagram shown in this figure. The resistances for the resistors are R, = 12 0, R. = 16 0, and R, = 22 0, respectively. The terminal voltage of the V battery is V = 22 V, and there is no internal resistance for this battery. Compute the voltage drop across resistor R2. Hint: First find the current in the circuit. Then R R3 use Ohm's low