Final answer:
The typical electric meter supply for a household in the U.S. is either 100 or 200 amps, with circuit breakers in homes rated between 10 to 30 amps for protecting appliances and residents.
Step-by-step explanation:
The typical supply for a square brand electric meter is either 100 amps or 200 amps. Given that houses in the U.S. are commonly equipped with circuit protection rated to either 100 or 200 Amps, options B) 150 amps and D) 250 amps are unlikely typical residential services. When a 100 A house operates at 80% of its capacity, it consumes power according to the formula P = I x V, where P is power in watts, I is current in amperes, and V is voltage. Therefore, the power consumed would be 80 amps (which is 80% of 100 amps) times 120 volts, equal to 9600 watts or 9.6 kilowatts. Over a month (assuming 30 days), the kWh consumed would be 9.6 kW x 24 hours/day x 30 days = 6912 kWh. At $0.15/kWh, the cost would amount to $1036.80.
Understanding the ratings of circuit breakers is crucial as they are designed to protect electrical circuits from damage caused by excess current. A 15-amp circuit can handle typical living room appliances while a 20-amp circuit is necessary for high-demand appliances like refrigerators. Circuit breakers act as safeguards for both the residents and the appliances in a household.