Electricity Test Review

Which of the following conditions must be met for electric current to flow through a circuit? (8a, DOK 1)

• The circuit must be a closed loop.

• The circuit must have a source of energized electric charges.

• A potential difference through the circuit must exist.

• All of the above.

Which of the following statements about Ohm’s Law is true?

• The current is inversely proportional to the voltage. (As current goes up, voltage goes down.)

• The current is inversely proportional to the resistance. (As resistance goes up, current goes down.)

• If the voltage in the circuit increases, then the current will decrease.

Which of the following would always increase the flow of current through the lights in the circuit?

• Increasing the battery voltage and increasing the resistance of the lights.

• Increasing the battery voltage and decreasing the resistance of the lights.

Students are building basic circuits in their physics class, and they are asked to measure the voltage across their circuit, which includes a battery and a single resistor. What must they do to get an accurate reading of the voltage? (8b, DOK 2)

• Students will need to use a voltmeter and touch it on either side of the battery in parallel to measure the voltage.

• Students will need to use a voltmeter built into the circuit in series with the resistor to measure the voltage.

• Students will need to use an ammeter and touch it on either side of the resistor in parallel to measure the voltage.

• Students will need to make the ammeter a component built into their circuit in series so that electrons flow through it to measure the voltage.

A group of students is conducting an investigation of a simple circuit with one bulb to find the resistance of the resistor. How should they measure current, and what relationship would they expect to find?  (8b, DOK 3)

• The students should measure the current with an ammeter connected in series (in line) with the resistor. They should find that as voltage increases, current decreases proportionally.

• The students should measure the current with an ammeter connected in series (in line) with the resistor. They should find that as voltage increases, current increases proportionally.

• The students should measure the current with an ammeter touching both ends of the resistor (parallel to the resistor). They should find that as voltage increases, current decreases proportionally.

Which of the three household objects costs the most to run per day, assuming the cost of electricity is the same? (power × time)

• The fan

• The stove

• The microwave

Tags

NGSS.HS-PS3-1

An automobile headlight with a resistance of 45.0 Ω is connected to a 20 V battery. What is the current through the circuit?

• 0.444 A

• 0.25 A

• 0.444 Volts

• 0.25 Volts

A circuit carrying a current of 12 A uses a power supply of 27 V. What is the power dissipated by the circuit?

• 110 Watts

• 56 Watts

• 324 Watts

• 5.2 Watts

Tags

NGSS.HS-PS3-5

Which of the following statements best describes a parallel circuit? (8c3, DOK 1)

• The voltage drop across each resistor is less than the total battery voltage.

• The current splits as it moves through the different branches of the circuit.

• The total resistance equals the sum of all the individual resistances in the circuit.

In which circuit will all the bulbs go out if one bulb is unscrewed?

• Circuit A

• Circuit B

• Does not apply