4.30 In the circuit shown in Fig. P4.30, D1 is a large-area, high-current diode whose reverse leakage is high and independent of applied voltage, while D2 is a much smaller, low-current diode. At an ambient temperature of 20°C, resistor R1 is adjusted to make VR1 = V2 = 520 mV. Subsequent measurement indicates that R1 is 520 kΩ. What do you expect the voltages VR1 and V2 to become at 0°C and at 60°C?