There is one IEC guideline, number is IEC 599, Statement of guideline is that "If the ratio of carbon dioxide and Carbon monoxide in Dissolve gas analysis test result is more than 11, it is predict that the condition of paper insulation inside the transformer is poor." For healthy condition this ratio will be between 4 to 11.
For t = 0 in RC circuit, After t = 0+ condition, capacitor is behave as short circuit. Voltage across the it 0. At final time, Capacitor is behave as open circuit, voltage across the capacitor at final time is equal to 15 V.
Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q