Solve problems involving Ohm’s Law and electric circuits

Please solve the following problems. You must show all work for full/partial credit. When complete, attach a typed cover sheet and submit to the assignment drop-box.

Question 1 (17 points):

How long would it take for a net charge of 2.5 C to pass a location in a wire if it is to carry a steady current of 5.0 mA?

Question 2 (18 points):

Two copper wires have equal lengths, but the diameter of one is three times that of the other.

• The resistance of the thinner wire is ____ times that of the thicker wire: (prove your work)
• 3
• 9
• ¼
• If the t wire has a resistance of 1.0 Ω, what is the resistance of the thinner wire?

Question 3 (17 points)

A 200 – W computer power supply is on 10 hours per day. If the cost of electricity is \$0.15/kWh, what is the cost (to the nearest dollar) to run the computer every day for a year (365 days)?

Question 4 (5 points)

What is the emf of a battery with an internal resistance of 0.15 Ω if the battery delivers 1.5 A to an externally connected 5.0 Ω resistors?

Question 5 (16 points)

Three resistors of value 1.0 Ω, 2.0 Ω, and 4.0 Ω are connected in a parallel circuit with a 6.0 V battery.

• What is the total equivalent resistance?
• What is the voltage across each resistor?
• The power delivered to the 4.0 Ω resistor?

Question 6 (10 points)

What is the equivalent capacitance of two capacitors of 0.40 µF and 0.60 µF when they are connected in:

• Series?
• Parallel?

Question 7 (17 points)

Three capacitors of equal capacitance are connected in parallel to a battery, and together they draw a certain amount of charge Q from that battery.

• Will the charge on each capacitor be:
• Q
• 3Q
• Q/3
• Three capacitors of 0.25 µF in each parallel connected to a 12-V battery. What is the charge on each capacitor?
• How much charge is drawn from the battery?