HOLT Problem Bank – Current and Circuits and SAT Bellringer Questions
3. A 9-Ω resistor is connected in series with another resistor across a 9.0-V battery. The current in the circuit is
0.33 A. Calculate the value of the unknown resistance.
4. A string of holiday lights has 73 light bulbs in series. Each light bulb has a resistance of 3.0 Ω. Calculate the
equivalent resistance.
8. A chandelier has 10 sockets wired in series, each of which holds a 10 Ω light bulb. If the voltage across the
chandelier’s circuit is 100 V, what is the total current?
4. A 39 Ω resistor, an 82 Ω resistor, a 12 Ω resistor and a 22 Ω resistor are connected in parallel across a potential
difference of 3.0 V. Calculate the equivalent resistance.
9. A lamp and a stereo are wired in parallel across a potential difference of 120 V. The lamp has a resistance of 11 Ω and
the stereo has a resistance of 36 Ω. How much current is in the branch with the lamp? How much is in the branch
with the stereo?
SAT Bellringer – Circuits and Circuit Elements
1. Two resistors, 2.50 Ω and 4.95 Ω, are wired in series to a 12.00 V battery. What is the equivalent resistance of the
circuit?
(A) 1.66 Ω
(B) 2.45 Ω
(C) 3.72 Ω
(D) 7.45 Ω
(E) 12.38 Ω
2. Two 3.5 Ω resistors and three 9.5 Ω resistors are connected in parallel. What is the equivalent resistance of the circuit?
(A) 0.028 Ω
(B) 0.89 Ω
(C) 1.1 Ω
(D) 2.6 Ω
(E) 36 Ω
3. A 15.00 Ω resistor and 7.00 Ω resistor are connected in parallel to a voltage source. A current of 1.50 A is in the 7.00 Ω
resistor. What is the potential difference (VOLTAGE) across the source?
(A) 7.16 V
(B) 10.5 V
(C) 14.7 V
(D) 16.5 V
(E) 33.0 V
Questions 5 and 6 are based on the following schematic diagram of a circuit with bulbs A, B, and C.
5. What is the equivalent resistance of the circuit?
(A) 0.0714 Ω (B) 0.875 Ω
(C) 1.14 Ω
(D) 4.67 Ω
(E) 14.0 Ω
6. If the current in the circuit is 10.5 A, what is the potential difference across the source?
(A) 0.750 V
(B) 9.19 V
(C) 12.0 V
(D) 49.0 V
(E) 147 V
Questions 9 and 10 are based on the following schematic diagram of a circuit with bulbs A, B, and C.
9. What is the equivalent resistance of the circuit?
(A) 0.0714 Ω (B) 0.214 Ω
(C) 0.875 Ω
(D) 1.14 Ω
(E) 4.67 Ω
10. If the current in bulb B is 8.50 A, what is the current in bulb C?
(A) 2.83 A
(B) 4.25 A
(C) 8.50 A
(D) 17.0 A
(E) 39.7 A
Power
1. A generator at a central electric power plant produces electricity with a potential difference of 2.5 × 104 V across power
lines which carry a current of 20.0 A. How much power does the generator produce?
2. An electric sports car was developed several years ago at Texas A&M University in College Station, Texas. If the
potential difference across the car’s motor is 720 V and the resistance was 0.30 Ω, how much power was needed for the
car to run?
7. A blender requires 350 W to power the rotating blades that chop food. If the blender has a resistance of
75 Ω, how much current passes through the blender’s circuit?