# Written midterm 1 - 2014

 Midterm date: 06 February 2014 (PDF) Midterm questions (PDF) Midterm questions and solutions
• Date: Thursday, 06 February
• Starting time: 18:30
• Duration: "infinite time" (within reason). The purpose of the infinite time is that time-induced pressure should not be a factor in the test; we want to see what you know.
• Locations:
• BSB 120: if lastname starts with A to H
• BSB 136, if lastname starts with I to R
• BSB 138, if lastname starts with S to Z

What will be covered in the midterm?'

The midterm will cover all material in the course, up to, and including 03 February 2014. This corresponds to material in Chapters 1 to 5 in Marlin's book, except for Chapter 4, section 5 (Frequency response).

• You may bring in any printed materials to the midterm; any textbooks, any papers, etc.
• You may use any calculator during the midterm.
• You may answer the questions in any order in the answer booklet.
• Time saving tip: never repeat the question back in your answer.
• If anything seems unclear, or information appears to be incomplete, please make a reasonable assumption and continue with the question.

How to prepare for the midterm

• Understand the concepts being learned. My courses are never about finding the right equation, plugging values in and solving. You will obviously need to use equations, but the end goal is demonstrate your understanding of the material, and that you can apply it to new situations.
• Read the questions carefully: they are usually worded precisely. The biggest point where students lose marks is to answer only one part of the question.
• Work through many of the practice questions on the website. They have full solutions.
• Work through all the tutorial problems again, making sure you understand the core concepts. The tutorials are posted on the course home page.
• An extra practice question was given here. The partial solutions to Question 2 are:

$\dfrac{C_I'(s)}{C_{I,0}'(s)} =\dfrac{1}{\frac{V}{F}s + 1} \\ V\dfrac{dC'_A}{dt} = \left(F + \dfrac{Vk_2}{1 +k_1C_{I,s} } \right)C_A' + \dfrac{Vk_1k_2C_{A,s}}{(1+k_1C_{I,s})^2}C_I'\qquad\text{where} \,\,k_2 = k_0e^{-E/RT}$

• Be sure you can explain why the gain is 1.0 for the first transfer function.
• The first ODE can be expressed in Laplace form as: $$\dfrac{C_I'(s)}{C_{I,0}'(s)} = \dfrac{K_I}{\tau_Is + 1}$$
• The second ODE can be expressed in Laplace form as: $$\dfrac{C_A'(s)}{C_I'(s)} = \dfrac{K_A}{\tau_As + 1}$$
• So the overall goal of the question can be achieved by multiplying transfer functions to obtain: $$\dfrac{C_I'(s)}{C_{I,0}'(s)} \cdot \dfrac{C_A'(s)}{C_I'(s)} = \dfrac{C_A'(s)}{C_{I,0}'(s)}$$