Skip to ContentGo to accessibility page
OpenStax Logo
Physics

Critical Thinking Items

PhysicsCritical Thinking Items

Critical Thinking Items

19.1 Ohm's law

11.

An accelerator accelerates He nuclei (charge = 2e) to a speed of v = 2 × 106 m/s. What is the current if the linear density of He nuclei is λ = 108 m–1?

  1. I = 9.6 × 10–5 A
  2. I = 3.2 × 10–5 A
  3. I = 12.8 × 10–5 A
  4. I = 6.4 × 10–5 A
12 .
How can you verify whether a certain material is ohmic?
  1. Make a resistor from this material and measure the current going through this resistor for several different voltages. If the current is proportional to the voltage, then the material is ohmic.
  2. Make a resistor from this material and measure the current going through this resistor for several different voltages. If the current is inversely proportional to the voltage, then the material is ohmic.
  3. Make a resistor from this material and measure the current going through this resistor for several different voltages. If the current is proportional to the square of the voltage, then the material is ohmic.
  4. Make a resistor from this material and measure the current going through this resistor for several different voltages. If the current is inversely proportional to the square of the voltage, then the material is ohmic.

19.2 Series Circuits

13.

Given three batteries (5V, 9V, 12V) and five resistors (10, 20, 30, 40, 50Ω) to choose from, what can you choose to form a circuit diagram with a current of 0.175A? You do not need to use all of the components.

  1. Batteries (5V, 9V) and resistors (30Ω, 50Ω) connected in series
  2. Batteries (5V4, 12V) and resistors (10Ω, 20Ω, 40Ω, and 50Ω) connected in series.
  3. Batteries (5V, 9V, and 12V) and resistors (10Ω, 20Ω, and 30Ω) connected in series.
14 .
What is the maximum resistance possible given a resistor of 100 and a resistor of 40 Ω ?
  1. 100 Ω
  2. 140 Ω
  3. 180 Ω
  4. 240 Ω
15.

Rank the points A, B, C, and D in the circuit diagram from lowest voltage to highest voltage.

  1. A, B, C, D
  2. B, C, A, D
  3. C, B, A, D
  4. D, A, B, C

19.3 Parallel Circuits

16 .
Can all resistor combinations be reduced to series and parallel combinations?
  1. No, all practical resistor circuits cannot be reduced to series and parallel combinations.
  2. Yes, all practical resistor circuits can be reduced to series and parallel combinations.
17.

What is the equivalent resistance of the circuit shown below?

Figure 19.23
  1. The equivalent resistance of the circuit 14 Ω.
  2. The equivalent resistance of the circuit 16.7 Ω.
  3. The equivalent resistance of the circuit 140 Ω.
  4. The equivalent resistance of the circuit 195 Ω.

19.4 Electric Power

18.

Two lamps have different resistances. (a) If the lamps are connected in parallel, which one is brighter, the lamp with greater resistance or the lamp with less resistance? (b) If the lamps are connected in series, which one is brighter? Note that the brighter lamp dissipates more power.

  1. (a) lamp with greater resistance; (b) lamp with less resistance
  2. (a) lamp with greater resistance; (b) lamp with greater resistance
  3. (a) lamp with less resistance; (b) lamp with less resistance
  4. (a) lamp with less resistance; (b) lamp with greater resistance
19.

To measure the power consumed by your laptop computer, you place an ammeter (a device that measures electric current) in series with its DC power supply. When the screen is off, the computer draws 0.40 A of current.
When the screen is on at full brightness, it draws 0.90 A of current. Knowing the DC power supply delivers 16 V, how much power is used by the screen?

  1. The power used by the screen is −8.0 W.
  2. The power used by the screen is 0.3 W.
  3. The power used by the screen is 3.2 W.
  4. The power used by the screen is 8.0 W.
PreviousNext
Order a print copy
Citation/Attribution
Reuse and redistribution of this content in digital or print format:
  • This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's prior written permission.
  • This book uses the Creative Commons Attribution License, which means that you can reuse and modify the material only for noncommercial purposes, must attribute Texas Education Agency (TEA), and must distribute any derivative works under the same license. The original material is available at: https://www.texasgateway.org/book/tea-physics . Changes were made to the original material, including updates to art, structure, and other content updates.
  • Any commercial printing of this textbook, including using a local or custom printer, must be approved by OpenStax, and proper citation provided.
  • OpenStax-copyrighted images, activities, assessments, and similar components of this book are subject to the same licensing – CC-BY-NC-SA. They can be used for noncommercial purposes with attribution. Commercial use requires permission.
  • Permission requests: Anyone who intends to incorporate this content (including text, images, and other components) into large language models, use it in AI offerings, use it commercially (including in print), and/or has questions about another use case is welcome to complete our reuse request form.
Attribution information
  • If you are redistributing all or part of this book in a noncommercial print format, then you must include on every physical page the following attribution:

    Access for free at https://openstax.org/books/physics/pages/1-introduction

  • If you are redistributing all or part of this book in a noncommercial digital format, then for every page that includes OpenStax content, you must license the derivative work under the same CC-BY-NC-SA license as the original, and include on every digital page view the following attribution:

    Access for free at https://openstax.org/books/physics/pages/1-introduction

Citation information

The information below includes the information needed to generate citations in most major styles (APA, MLA, etc.); you must reformat and organize the information as needed to fit the requirements of the style. Use the information below to generate a citation. We recommend using a citation tool such as this one.

© Jul 8, 2026 Texas Education Agency (TEA). The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo, and Rice University name, and Rice University logo trademarks, or wordmarks are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.