Unit Test : Physics : Electric Circuits 96%

A noncontinuous loop that prevents the flow of current is a(n) __________ circuit.

open

A disrupted circuit in which the current bypasses its proper path is a(n) ________ circuit.

short

A current of 6.0 A runs through a circuit for 2.5 minutes. How much charge was delivered to this circuit? A. 15 C B. 25 C C. 600 C D. 900 C

A. 15 C

Which equation relates charge, time, and current? A. I = delta q/t B. I= t/ delta q C. I= delta q t D. I = delta q + t

A. I = delta q/t

For a constant voltage, how is the resistance related to the current? A. Resistance is inversely proportional to current, so when the resistance doubles, the current is cut in half. B. Resistance is directly proportional to current, so when the resistance doubles, the current is cut in half. C. Resistance is inversely proportional to current, so when the resistance doubles, the current doubles. D. Resistance is directly proportional to current, so when the resistance doubles, the current doubles.

A. Resistance is inversely proportional to current, so when the resistance doubles, the current is cut in half.

The cause of a fire in a computer is described as an incorrectly wired circuit. Which statement best explains the likely cause of the fire? A. The wiring contained a short circuit, so the reduced resistance caused an increase in current. B. The wiring contained an open circuit, so the reduced resistance caused an increase in current. C. The wiring contained a closed circuit, so the current was redirected around the components that would have provided the proper resistance. D. The wiring contained an open circuit, so the current was redirected around the components that would have provided the proper resistance.

A. The wiring contained a short circuit, so the reduced resistance caused an increase in current.

Bruce collects the data on four electric circuits listed in the table. Bruce must report any circuits that deliver more than 4.0 C of charge in 8.0 s. Which lists every circuit that Bruce must include in his report? A. X and Z B. X and Y C. W and Y D. W and Z

A. X and Z

A circuit that has only a single path for current to flow through is best classified into which category? A. a series circuit B. an open circuit C. a parallel circuit D. a short circuit

A. a series circuit

What is a path through which electric charges travel? A. electric circuit B. resistance C. voltage D. electric current

A. electric circuit

Which changes would cause an increase in the resistance of a wire? Check all that apply A. increasing its temperature B. decreasing its temperature C. using a longer wire D. using a shorter wire E. using a thicker wire F. using a thinner wire

A. increasing its temperature C. using a longer wire F. using a thinner wire

Which quantities are equal to total of the individual values within a circuit? A. the current in a parallel circuit and the voltage in a series circuit B. the resistance in a parallel circuit and the current in a series circuit C. the resistance in a parallel circuit and the voltage in a series circuit D. the voltage in a parallel circuit and the resistance in a series circuit

A. the current in a parallel circuit and the voltage in a series circuit

Current 1 of 8.4 A runs for 240 seconds and then stops. Current 2 is 10.5 A. How long does current 2 have to run to deliver the same amount of charge as current 1? A. 88.2 s B. 192 s C. 2016 s D. 21,000 s

B. 192 s

What is the continuous flow of electric charge? A. voltage B. resistance C. potential difference D. current

D. current

The circuit diagram shows a circuit containing several different components. Which correctly describes the number of one type of component in this circuit? A. two batteries B. two switches C. three bulbs D. three resistors

D. three resistors

Which statement correctly describes the formation of an electric current? A. resistance causes electric charges to move from lower to higher potential. B. voltage causes electric charges to move from lower to higher potential. C. resistance causes electric charges to move from higher to lower potential. D. voltage causes electric charges to move from higher to lower potential.

D. voltage causes electric charges to move from higher to lower potential.

A ceiling fan draws a current of 0.625 A and has a voltage of 120 V. The resistance of the ceiling fan, to the nearest whole number, is __________.

192 Ω

A circuit carries a current of 0.64 A when there is a resistance of 50.0 Ω. The voltage applied to the circuit, to the nearest whole number, is ________.

32 V

A circuit has a resistance of 2.5 Ω and is powered by a 12.0 V battery. The current in the circuit, to the nearest tenth, is __________

4.8 A

Humberto builds two circuits using identical components. Circuit 1: A series circuit with three lightbulbs Circuit 2: A parallel circuit with three lightbulbs He then adds two more lightbulbs in a series with the bulbs in circuit 1 and two more lightbulbs on new branches in parallel with each bulb in circuit 2. -- What can he expect to see? A. All bulbs in circuit 1 will shine at the same brightness as the original bulbs, while all bulbs in circuit 2 will be dimmer than the original bulbs. B. All bulbs in circuit 1 will shine more dimly than the original bulbs, while all bulbs in circuit 2 will have the same brightness as the original bulbs. C. The original bulbs will remain at their original brightness, but the bulbs added to circuit 1 will be dimmer than the bulbs added to circuit 2. D. The original bulbs will remain at their original brightness, but the bulbs added to circuit 1 will be brighter than the bulbs added to circuit 2.

B. All bulbs in circuit 1 will shine more dimly than the original bulbs, while all bulbs in circuit 2 will have the same brightness as the original bulbs.

Jason sees a news report about a traffic jam caused by a truckload of tires that spilled across the road. The next day in class, he uses the traffic jam as an analogy to explain electric circuits to his friend. Which is most likely the analogy that Jason used? A. The cars represent moving charges, and the spilled tires represent an increased voltage that causes the current to decrease. B. The cars represent moving charges, and the spilled tires represent an increased resistance that causes the current to decrease. C. The tires represent moving charges, and the cars represent an increased resistance that causes the current to decrease. D. The tires represent moving charges, and the cars represent an increased voltage that causes the current to decrease.

B. The cars represent moving charges, and the spilled tires represent an increased resistance that causes the current to decrease.

What is the unit for measuring electric current? A. volt B. ampere C. ohm D. coulomb

B. ampere

What is the tendency of a material to oppose the flow of charge? A. voltage B. resistance C. potential difference D. current

B. resistance

Cici uses a long extension cord to plug a lamp into a wall outlet in the next room. What effect will the extension cord have on the circuit? A. It will decrease the resistance of the circuit. B. It will increase the voltage of the outlet. C. It will increase the resistance in the circuit. D. It will decrease the voltage of the outlet.

C. It will increase the resistance in the circuit.

A circuit featuring multiple paths through which current can flow is best classified into which category? A. a series circuit B. an open circuit C. a parallel circuit D. a short circuit

C. a parallel circuit

Jonas sees this symbol in a circuit diagram. Which circuit component does the symbol represent? A. resistor B. bulb C. battery D. voltmeter

C. battery