Free Certified Energy Manager (CEM) Practice Test
The Certified Energy Manager Exam is a certification examination written and administered by the Certified Energy Manager Board that is designed to determine if an individual possesses the skills and knowledge necessary to receive the Certified Energy Manager (CEM) credential. The CEM credential is not necessarily required to work as an energy manager, but it can be extremely useful as a resume-builder for individuals seeking positions in the energy management field as it demonstrates to potential employers that the individual has an in-depth knowledge of the laws, standards, common practices, and concerns associated with energy management. This exam assesses the individual's knowledge of general energy topics such as energy codes and standards, indoor air quality, energy accounting, energy economics, energy audits, and energy instrumentation. It also examines the individual's knowledge of a variety of specialized topics related to energy management.
The CEM exam is an open book exam that consists of a large number of multiple-choice questions that are split into 17 sections. The exam-taker is not required to complete every section of the CEM exam, but is instead required to take the first three sections of the CEM exam, which includes the general topics mentioned above, and must choose and complete 8 additional sections from the 14 specialized sections offered. The specialized sections offered on the CEM exam include alternative financing, boiler and steam systems, building automation and control systems, building envelope, cogeneration and CHP systems, electrical systems, energy procurement, green buildings, HVAC systems, industrial systems, lighting systems, maintenance and commissioning, motors and drives, and thermal energy storage systems.
The exam-taker will have four hours to complete the CEM exam and the exam is scored on a scale of 0 - 1040 with 704 set as the minimum score required to pass the CEM exam. Each question on the CEM exam is worth 8 points, but points will only be awarded for correct responses made within the first 3 sections of the CEM exam and the first 8 additional sections marked by the exam-taker. In order to register for the CEM exam, the individual must have a bachelor's degree or higher from an engineering program and at least 3 years of experience in energy engineering or management, a bachelor's degree or higher from a business program and at least 5 years of experience in energy engineering or management, an associate's degree from a technical program and at least 8 years of experience in energy engineering or management, or 10 years of experience in energy engineering or management. The registration fee for the CEM exam is currently $200.
1. In an Orsat apparatus, the gas remaining after the introduction of flue gas is assumed to be:
b. carbon monoxide.
c. carbon dioxide
d. potassium hydroxide.
e. cuprous chloride.
2. Which of the following lighting systems is affected the least by a 10 percent reduction in voltage?
a. Incandescent lighting systems
b. Mercury lamps
c. Fluorescent lighting systems
d. High-intensity discharge lamps
e. Low-intensity discharge lamps
3. Which of the following variables is NOT considered in the calculation of a light loss factor?
a. Depreciation of lamp lumen due to the buildup of dirt
b. Loss of lamps due to breakage
c. Depreciation of the lamp lumen over time
d. Rate at which lamps burn out
4. The seasonal efficiency of natural gas heating equipment is:
a. greater than the seasonal efficiency of oil heating equipment.
b. less than the seasonal efficiency of oil heating equipment.
c. about the same as the seasonal efficiency of oil heating equipment.
5. Which substance produces the most efficient high-intensity discharge lamps?
b. High-pressure sodium
c. Metal halide
e. Tungsten halogen
Answers & Explanations
1. A: In an Orsat apparatus, the gas remaining after the introduction of flue gas is assumed to be nitrogen. The Orsat apparatus is the best piece of equipment for analyzing stack gas. This is important because excessive levels of molecular oxygen indicate an inefficient boiler. Similarly, there may be a health hazard if the boiler is producing too much carbon monoxide. In an Orsat apparatus, there is a tube of potassium hydroxide, the tube of cuprous chloride, and a tube of potassium pyrogallate. Flue gas is introduced to each of these tubes, and the amount of carbon dioxide, carbon monoxide, and oxygen, respectively, that is removed suggests the extent to which these latter gases are present in the flue gas.
2. C: Fluorescent lighting systems are considerably less compromised by a 10 percent reduction in voltage than incandescent lighting systems and mercury, high-intensity discharge, and low-intensity discharge lamps. Typically, a 10 percent reduction in voltage will only diminish light output by 15 percent in a fluorescent lighting system, whereas in incandescent, mercury, high-intensity discharge, and low-intensity discharge systems, the decrease will be more like 30 percent.
3. B: The loss of lamps due to breakage is not considered in the calculation of a light loss factor. The basic light loss factor is determined by multiplying the rate at which lamps depreciate due to dirt by the rates at which they burn out and depreciate in brightness over time. Of course, this is an inexact measure. However, it is generally assumed that efforts to reduce the depreciation of lamps will require more frequent replacement.
4. C: The seasonal efficiency of natural gas heating equipment is about the same as the seasonal efficiency of oil heating equipment. For both types of equipment, seasonal efficiency is between 30 percent and 60 percent. This is in contrast to the rated efficiency of oil and gas heating equipment, which is typically between 70 percent and 80 percent. Whereas rated efficiency is the efficiency value indicated in a manufacturer's catalog, seasonal efficiency is the actual efficiency of the equipment in practice. A number of factors contribute to this slightly less efficient performance in real life.
5. B: High-pressure sodium produces the most efficient high-intensity discharge lamps. Moreover, this type of lamp maintains its quality very well over its entire life. In recent years, manufacturers have done an excellent job of creating high-pressure sodium lamps in a range of acceptable interior colors. The other two types of high-intensity discharge lamp are mercury vapor and metal halide. Both of these lamps are efficient relative to other light sources, though they do not quite reach the efficiency level of the high-pressure sodium lamp.
Last Updated: 03/01/2017