Quiz 5 - Electric Current and Circuits

The power of a toaster can be determined if which of the following values are known?

• the dimensions of the toaster

• the resistance of the toaster's insulation

• the voltage applied to the toaster and the toaster's temperature

• the current through the circuit and the voltage applied to the toaster

The measurements in the table below are from four circuits that have the same components except for the battery. Which of the following statements describes how voltage, current, and resistance are related by Ohm’s law in these circuits?

• As voltage increases, current decreases and resistance decreases.

• As voltage increases, current increases and resistance stays the same.

• As voltage increases, current decreases and resistance stays the same.

• As voltage increases, current stays the same and resistance decreases.

The diagram below shows an electrical circuit. Which of the following best explains why energy stored in the battery power source diminishes over time when this circuit is complete?

• The power source generates energy more slowly than the light bulb consumes it.

• The light bulb converts the negative charge of electrons into light and heat.

• The light bulb transforms energy into light and heat.

• Energy is destroyed when the light bulb operates.

The distance between two charges is represented by d. In which of the following diagrams is the attractive force between the two charges the greatest?

• Diagram A

• Diagram B

• Diagram C

• Diagram D

Which of the following conditions results in the buildup of static charge on an object?

• when neutrons outnumber electrons

• when there are more protons than neutrons

• when there are more electrons than protons

• when all neutrons have been removed from the object

A copper sphere, a glass sphere, a plastic sphere, and a rubber sphere are placed on individual insulating stands. A student touches each sphere with an electrically charged object. The sphere made of which material will distribute the electric charge fastest over its entire surface area?

• glass

• copper

• plastic

• rubber

The graph below relates the current to voltage data for a resistor. Which of the following is the value of the resistor?

• 0.2 Ω

• 2.0 Ω

• 4.0 Ω

• 10.0 Ω

The two resistors shown below are connected to identical power sources. Resistor 1 has a resistance of 30 Ω, and resistor 2 has a resistance of 45 Ω. The current in resistor 1 is 2 A. What is the current in resistor 2?

• A. 1.0 A

• B. 1.3 A

• C. 1.5 A

• D. 3.0 A

What is the voltage across the terminals of a 23 Ω resistor that has 0.065 A of current flowing through it?

• A. 0.0028 V

• B. 0.097 V

• C. 1.5 V

• D. 350 V

The diagram below shows a simple electric circuit. Which of the following statements describes the function of the battery?

• It reduces the flow of electrons.

• It transmits light through the circuit.

• It pushes electrons through the circuit.

• It releases light during a chemical reaction.