Question

Use the worked example above to help you solve this problem. An electrical heater is operated by applying a potential difference of 49.4 V to nichrome wire of total resistance 8.04 Ω. (a) Find the current

asked Jul 25, 2021 145k views

Use the worked example above to help you solve this problem. An electrical heater is operated by applying a potential difference of 49.4 V to nichrome wire of total resistance 8.04 Ω. (a) Find the current carried by the wire and the power rating of the heater. I = 6.14 Correct: Your answer is correct. A P = 303.5 Correct: Your answer is correct. W (b) Using this heater, how long would it take to heat 2.10 103 moles of diatomic gas (e.g., a mixture of oxygen and nitrogen, or air) from a chilly 10°C to 25°C? Take the molar specific heat at constant volume of air to be 5 2 R. s (c) How many kilowatt-hours of electricity are used during the time calculated in part (b) and at what cost, at $0.14 per kilowatt-hour? U = kWh cost $ EXERCISEHINTS: GETTING STARTED | I'M STUCK! (a) A hot-water heater is rated at 4.69 103 W and operates at 2.40 102 V. Find the resistance in the heating element and the current. R = Ω I = A (b) How long does it take to heat 125 L of water from 25.6°C to 54.0°C, neglecting conduction and other losses? (The specific heat of water is 4.186 J/g · K.) s (c) How much does it cost at $0.14/kWh? $