Download - Franklin High School

AP Physics – Current Electricity Review
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How is current affected if the number of charge carriers decreases?
How is current affected if the time interval decreases (charge remains the same).
The current in a device is 5.0 µA. How much charge moves through the device in 10 s?
Two protons are separated by a distance of 2.5 μm. What is the electric force between the two
electrons?
5. IF two point charges are separated by 1.5 cm and have charge values of 2.0 μC and -4.0 μC
respectively, what is the value of the mutual force between them?
6. If the two point charges in the previous question are moved to a distance of 4.5 cm, what would
the force be?
7. How do electrons move through a metal conductor?
8. How do electrons move in alternating current?
9. How do electrons move in direct current?
10. What is the potential difference across a resistor of 10.0 ohms that carries a current of 5.0 amps?
11. A device has a resistance of 480 Ω when operating at 120 V. What is the current in the device?
12. List some variables that affect a material’s resistance.
13. Which of the following would have the least resistance.
a. A wire 20 cm in length.
b. A wire 50 cm in length.
a. A wire 1 mm in diameter.
b. A wire 3 mm in diameter.
a. A wire 20 cm in length at 20° C.
b. A wire 20 cm in length at 80°C.
14. What does a light bulb’s power rating measure?
15. If a 100 W light bulb operates at a voltage of 240 V, what is the current in the bulb?
16. If a 1000 W heater has a current of 5.0 A, what is the potential difference across the ends of the
heating element?
17. If a lamp has a resistance of 150 Ω when it operates at a power of 500 W. What is the potential
difference across the lamp?
18. If a device has a resistance of 50 Ω when it operates at a power of 50 W, what is the current in
the lamp?
19. A high voltage transmission lines carries 100 A at 120,000 V. What is the maximum power carried
in the line?
20. If the potential difference across 3 batteries in a flashlight is 4.5 V, what is the potential
difference across the bulb?
21. How does the potential difference across the bulb in a flashlight compare with the terminal
voltage of the batteries?
22. Three resistors with values of 5.0 Ω, 10 Ω, and 20 Ω, are connected in series. What is the
equivalent resistance?
23. Three resistors connected in series carry currents labeled I1, I2, and I3 respectively. How would
you express the total current in the system?
24. Three resistors connected in series have voltages labeled V1, V2, and V3. How would you
express the total voltage in the system?
25. Three resistors with values of R1, R2, and R3 are connected in series. How would you express the
total resistance of the system?
26. Three resistors with values of 4.0 Ω, 6.0 Ω, and 10.0 Ω, are connected in parallel. What is
their equivalent resistance?
27. Three resistors connected in parallel carry currents labeled I1, I2, and I3. How would you
express the total current in the system?
28. Three resistors connected in parallel have voltages labeled V1, V2, and V3. How would you
express the total voltage in the system?
29. Three resistors with values of R1, R2, and R3 are connected in parallel. How would you
express the total resistance in the system?
30. What is the equivalent resistance of the following circuit?
31. What is the equivalent resistance of the following circuit?
32. What is the equivalent resistance of the following circuit?
33. What is the equivalent resistance of the following circuit?
34. What is the equivalent resistance of the following circuit?
35. What is the current across the battery of the following circuit? (The potential difference is 60 V
and each resistor is 100 Ω each.)
36. Fill in the blanks in the following diagram. Show appropriate units. B1 = 30.0 V,
R1 = 10.0 Ω, R2 = 10.0 Ω, R3 = 10.0 Ω.
RT = _______
IT = _______
I1 = _______
V1 = _______
I2 = _______
V2 = _______
I3 = _______
V3 = _______
37. Three capacitors with values of C1, C2, and C3 are connected in parallel. How would you
express the total capacitance in the system? How would you express the total capacitance
if the capacitors were in series?
38. What happens to the current in a series circuit when more resistors are added? In parallel?
39. Why are batteries connected in series? In parallel?
40. Calculate the terminal voltage for a battery with an internal resistance of 0.800 Ω and an
emf of 12.0 V when the battery is connected in series with a 35.0 Ω resistor.
41. Four identical capacitors are connected to a battery. Will they store more energy if they are
connected in series or parallel?
42. You have four capacitors; 200 μF, 400 μF, 600 μF, and 800 μF. What is the maximum and
minimum capacitance that you can form from these?
43. A 4.00 μF capacitor is connected to a 12.0 V battery. What is the charge on the capacitor?