Sprinkler heads used in computer rooms activate at what temperature?
Answer : A
Sprinkler heads used in computer rooms activate at 57 C (135 F), which is the standard temperature rating for ordinary sprinklers. This is the temperature at which the heat-sensitive element of the sprinkler head, such as a glass bulb or a fusible link, breaks or melts, allowing water to flow from the sprinkler. Sprinkler heads are designed to activate only when exposed to a fire, not to ambient temperature fluctuations. Therefore, sprinkler heads should be installed at a sufficient distance from the heat sources, such as servers, racks, or ducts, to avoid accidental activation. Sprinkler heads should also be selected and installed in accordance with the relevant standards and codes, such as NFPA 13 and NFPA 75.
1: CDCP Preparation Guide, page 24, section 2.4.3 2: Sprinkler Systems in Data Centers3, page 1, section 1 4: Data Center Fire Protection5, page 1, section 2 6: Data Center Sprinkler System Design7, page 1, section 1
Which one of the following is an example of Direct Cost?
Answer : A
Legal fees are an example of direct cost because they can be directly attributed to a specific project, product, or service. Legal fees are incurred for the purpose of obtaining legal advice, drafting contracts, resolving disputes, or complying with regulations related to the core business activity. Legal fees are not general overhead expenses that are shared by multiple cost objects.
By what are magnetic fields of the type 'H' or 'B' created?
Answer : A
According to the CDCP Preparation Guide1, magnetic fields of the type 'H' or 'B' are created when an electric current flows through a conductor, such as a wire or a coil. The magnetic field strength 'H' is proportional to the current 'I' and the number of turns 'N' of the coil, and inversely proportional to the length 'l' of the coil. The magnetic flux density 'B' is proportional to the magnetic field strength 'H' and the permeability '' of the medium in which the magnetic field exists. The greater the current, the stronger the magnetic field and the magnetic flux density. The relationship between 'H', 'B', 'I', 'N', 'l', and '' can be expressed by the following equations:
H = N I / l
B = H
1: CDCP Preparation Guide, page 23, section 2.4.2.1 2: Difference between B and H in magnetic fields?3, page 1, section 1 4: Magnetic field | Definition & Facts5, page 1, section 1
Which source is used in fiber cable to transmit data?
Answer : C
Fiber-optic cables use light as the source to transmit data. Light pulses are modulated to carry information through an optical fiber. The light is confined in the core of the fiber by total internal reflection at the core-cladding interface. The light travels along the fiber with minimal loss or interference, making it suitable for long-distance and high-bandwidth applications.
An optical fiber cable comes with the specifications 50/125 um.
What do the numbers represent?
Answer : B
Optical fiber cables are composed of a core, a cladding, and a coating. The core is the central part of the fiber that carries the light signal. The cladding is the layer surrounding the core that reflects the light back into the core and prevents signal loss. The coating is the protective layer that covers the cladding and provides mechanical strength and environmental protection. The specifications of an optical fiber cable indicate the dimensions of the core and the cladding in microns (m), which are one millionth of a meter. For example, a 50/125 m cable has a core diameter of 50 m and a cladding diameter of 125 m. The coating diameter is usually 250 m, but it is not part of the specifications.
Which one of the following is an Objective of Data Center Fire Protection?
Answer : D
The objective of data center fire protection is to suppress or extinguish a fire before it can cause significant damage to the equipment, personnel, or business continuity. Fire suppression systems are designed to reduce the heat, oxygen, or fuel elements of the fire triangle, and to limit the spread of fire and smoke. Fire suppression systems can be classified into two types: water-based and gas-based. Water-based systems include sprinklers, mist, and water spray systems, which use water as the extinguishing agent. Gas-based systems include inert gas, halocarbon, and clean agent systems, which use gases or chemicals as the extinguishing agent. The choice of fire suppression system depends on several factors, such as the fire risk, the type of fuel, the environmental impact, the reliability, the cost, and the compatibility with the data center equipment and operations.
* EPI Data Centre Professional (CDCP) Preparation Guide, page 31
* A Comprehensive Approach To Data Center Fire Safety
Which one of the following does a Physical Infrastructure consists of in a Data Centre?
Answer : C
A physical infrastructure in a Data Center consists of racks, which are metal frames used to store and organize server and other IT equipment. The racks are usually arranged in rows and columns, and they can be used to hold servers, storage devices, and other pieces of IT equipment. The racks can also be used to organize cables and other components to ensure that the Data Center is kept organized and efficient.