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5.) A bulb is plugged into a 120 Volt outlet. The resistance of the bulbs is 330 ohms.

a. Calculate the current through the bulb.
b. Calculate the watts and kw.
c. Calculate the cost to run the bulb for 10 hours at 8 cents/ kWhr.

1 Answer

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Answer:

a. The current through the bulb can be calculated using Ohm's law, which states that current is equal to voltage divided by resistance:

I = V/R = 120 V / 330 ohms = 0.36 A

Therefore, the current through the bulb is 0.36 A.

b. The power of the bulb can be calculated using the formula P = VI, where P is power, V is voltage, and I is current:

P = VI = (120 V) x (0.36 A) = 43.2 W

Therefore, the power of the bulb is 43.2 watts or 0.0432 kW.

c. To calculate the cost to run the bulb for 10 hours at 8 cents/ kWhr, we need to first calculate the energy consumption in kilowatt-hours (kWh):

Energy consumption = power x time

Energy consumption = 43.2 W x 10 hours = 432 Wh = 0.432 kWh

The cost can now be calculated by multiplying the energy consumption by the cost per kWh:

Cost = energy consumption x cost per kWh

Cost = 0.432 kWh x $0.08/kWh

Cost = $0.03456

Therefore, the cost to run the bulb for 10 hours at 8 cents/ kWhr is $0.03456.

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