28. An 11.0 W energy-efficient fluorescent lightbulb is designed to produce the same illumination as a conventional 40.0 W incandescent lightbulb. Assuming a cost of $0.110 kWh for energy from the electric company, how much money does the user of the energy- efficient bulb save during 100 h of use?

One day on a particularly stormy night, a science student is watching the rain and thinking about all the homework they have to do. Just then a bolt of lightning discharges 21 C from one cloud to a power line. The student was able to use their iPhone to measure the potential difference to be 15,050 volts. With this data, how much energy is lost by the cloud and gained by the power line? O O a b с Od 316,050 J 442,470 J 94,815J 221,235 J

A 180.0 V power line is protected by a 20 A fuse. What is the maximum number of 405 W lamps that can be simultaneously operated in parallel on this line without "blowing" the fuse because of an excess of current?

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A 1750 W radiant heater is constructed to operate at 120 V. What is the current in the heater when the unit is operating? What is the resistance of the heating coil? How much thermal energy is produced in 2.0 h?

DETAILS SHIPPS15 8.2.E.018. A 13.0 W LED light bulb is turned on. It has an operating voltage of 120 V. (a) How much current (in A) flows through the bulb? (b) What is the resistance (in 0) of the bulb? (c) How much energy (in J) is used each second? J each second

Problem 6:  Suppose the cost of an incandescent bulb is 23 cents and that electricity costs 12 cents/kWh. Compact fluorescent lightbulbs (CFL), while they are more expensive, use 1/10 of the power for the same amount of illumination. What would be the maximum cost (in dollars) of a CFL such that the total cost (investment plus operating) would be the same for both CFL and incandescent 60 W bulbs? Assume both lightbulbs run for 1000 h.

A 9 W led lightbulb emits the same light as a 60 W standard lightbulb. If a power company charges 10 cents per kW.h, then how much money do you save by using the led lightbulb instead of the standard lightbulb for 30 days?

B04

A physics student has a single-occupancy dorm room. The student has a small refrigerator that runs with a current 2 A, a lamp that contains a 100-W bulb, an overhead light with a 60-W bulb, and various other small devices adding up to 7 W. All the appliances run on a voltage of 110 V. Overall Hint a. What is the total power used by the dorm room (while the refrigerator runs)? Total power used by the dorm room is b. Assuming that the power plant for the electricity is 16 km away and uses 000-gauge copper wire (diameter 10.405 mm), how much power is dissipated in transmission (remember to count the return wire), if the power plant is directly providing the 110-V? (To be more precise, the power plant is providing the voltage it needs to provide, so that the voltage at the dorm room is 110 V.) Hint for part (b) Power of W is dissipated in transmission at 110 V. c. The most common way to increase the efficiency of power transmission is by using higher voltage for long-distance transmission…