1.
Which heat detectors can be the slowest to acitvate?
Correct Answer
D. Fixed-temperature heat detectos
Explanation
Fixed-temperature heat detectors can be the slowest to activate because they are designed to activate only when a specific temperature threshold is reached. Unlike other types of heat detectors, such as ionization or rate-of-rise detectors, fixed-temperature detectors do not respond to changes in temperature or smoke. They rely on a predetermined temperature setting, typically set at a higher threshold, to trigger an alarm. This means that fixed-temperature detectors may take longer to activate in a slow and steady temperature rise scenario, compared to detectors that are more sensitive to changes in temperature or smoke particles.
2.
Which heat detectors operate on the assumption that the temperature in a room will increase faster from a fire than from normal atmospheric heating?
Correct Answer
B. Rate-of-Rise heat detectors
Explanation
Rate-of-Rise heat detectors operate on the assumption that the temperature in a room will increase faster from a fire than from normal atmospheric heating. These detectors are designed to detect rapid increases in temperature, such as the sudden rise in temperature caused by a fire. They are able to quickly sense the change in temperature and trigger an alarm, alerting individuals to the presence of a fire. This makes them effective in detecting fires in their early stages, providing valuable time for evacuation and firefighting efforts.
3.
Which Heat detectors are relatively inexpensive?
Correct Answer
D. Fixed-temperature heat Detectors
Explanation
Fixed-temperature heat detectors are relatively inexpensive compared to other types of heat detectors. This is because fixed-temperature heat detectors operate on a simple principle whereby they are designed to activate once a specific temperature threshold is reached. They do not incorporate complex mechanisms or sensors like ionization or photoelectric heat detectors, which makes them cheaper to produce. Therefore, fixed-temperature heat detectors are a cost-effective option for detecting heat in certain environments.
4.
Which heat detectors are reliable and not subject to false activations?
Correct Answer
B. Rate-of-Rise heat detectors
Explanation
Rate-of-Rise heat detectors are reliable and not subject to false activations because they are designed to detect rapid increases in temperature. These detectors are equipped with a sensor that measures the rate at which the temperature is rising, and if it exceeds a certain threshold, an alarm is triggered. This type of heat detector is particularly effective in detecting fires that produce a quick and significant increase in temperature, such as flammable liquid fires or electrical fires. Unlike other types of heat detectors, rate-of-rise detectors are less likely to be triggered by normal fluctuations in temperature or non-fire related sources, making them more reliable in accurately detecting fires.
5.
Which of the following is a disadvantage of fixed-temperature heat detectors?
Correct Answer
D. They activate only after the fire has been burning for quite some time
Explanation
Fixed-temperature heat detectors have a disadvantage in that they activate only after the fire has been burning for quite some time. This means that by the time they detect the fire, it may have already grown significantly in size and intensity. This delayed activation can result in a slower response time and potentially more damage before the fire is detected and appropriate action is taken.
6.
Fixed-temperature heat detectors are installed on the ____ of a room
Correct Answer
B. Ceiling
Explanation
Fixed-temperature heat detectors are installed on the ceiling of a room because heat rises. By installing the detectors on the ceiling, they are positioned in the area where the highest temperature is likely to be during a fire. This allows for early detection and activation of the alarm system, providing more time for evacuation and firefighting efforts. Installing the detectors on the floor, middle, or lower half of the room would not be as effective in detecting heat and alerting occupants to a potential fire.
7.
Fixed-temperature heat detectors reated at _______ * F (*C) are common for living spaces.
Correct Answer
A. 165 (76)
Explanation
Fixed-temperature heat detectors are commonly used in living spaces because they are designed to activate at a specific temperature, in this case, 165°F (76°C). These detectors are important for fire safety as they provide an early warning when the temperature reaches a certain level, allowing people to evacuate the area and take necessary precautions. By activating at a specific temperature, these detectors help to minimize false alarms while ensuring that they are sensitive enough to detect a potential fire.
8.
Which of the following is NOT one of the ways by which a fixed-temperature heat detector activates?
Correct Answer
B. Explosion of heated material
Explanation
A fixed-temperature heat detector activates when the temperature reaches a certain threshold. The melting of heated material, expansion of heated material, and changes in resistance of heated material are all valid ways by which a fixed-temperature heat detector can activate. However, the explosion of heated material is not a typical way for a fixed-temperature heat detector to activate.
9.
Which fixed-temperature heat detector holds a spring-operated contact inside the detector in the open position?
Correct Answer
A. Fusible Device
Explanation
A fusible device is a fixed-temperature heat detector that holds a spring-operated contact inside the detector in the open position. When the temperature reaches a certain threshold, the fusible material inside the device melts, causing the spring to release and close the contact. This triggers an alarm or activates a fire suppression system. The other options, frangible bulb, photoelectric detector, and continuous line detector, do not have the same mechanism of holding a spring-operated contact in the open position.
10.
Which fixed-temperature heat detector is a glass vial that contains a liquid with a small air bubble?
Correct Answer
B. Frangible bulb
Explanation
A frangible bulb is a fixed-temperature heat detector that consists of a glass vial containing a liquid with a small air bubble. When exposed to a certain temperature, the liquid inside the bulb expands, causing the glass to break and release the air bubble. This breakage triggers an alarm or activates a fire suppression system. Therefore, a frangible bulb is the correct answer for this question.
11.
Which fixed-temperature heat detector detects heat over a linear area parallel to the detector?
Correct Answer
D. Continuous line detector
Explanation
A continuous line detector is capable of detecting heat over a linear area parallel to the detector. Unlike other options listed, such as a fusible device or a frangible bulb, which are designed to respond to heat at a specific point or area, a continuous line detector is specifically designed to detect heat along a continuous line. This makes it suitable for applications where heat detection over a larger area is required, such as in industrial settings or large-scale fire detection systems. A photoelectric detector, on the other hand, uses light rather than heat to detect fire or smoke, so it is not the correct answer in this context.
12.
Rate-of-rise heat detectors are designed to initiate a signal when the rise in termpaerature exceeds ___ *F (*C) in one minute.
Correct Answer
B. 12 to 15 (-11 to -9)
Explanation
Rate-of-rise heat detectors are designed to initiate a signal when the rise in temperature exceeds 12 to 15 degrees Fahrenheit (-11 to -9 degrees Celsius) in one minute.
13.
Which rate-of-rise heat detector is the most common type?
Correct Answer
D. Pneumatic rate-of-rise spot detector
Explanation
The most common type of rate-of-rise heat detector is the pneumatic rate-of-rise spot detector. This type of detector uses a pneumatic mechanism to detect changes in temperature. It is designed to quickly respond to rapid increases in temperature, making it suitable for detecting fires. The spot detector refers to its ability to detect temperature changes in a specific spot or location. This type of detector is widely used in various industries and buildings for fire detection and prevention purposes.
14.
Which rate-of-rise heat detector consists of a system of tubing arranged over a wide area of coverage?
Correct Answer
C. Pneumatic rate-of-rise line detector
Explanation
A pneumatic rate-of-rise line detector consists of a system of tubing arranged over a wide area of coverage. This type of heat detector is designed to detect rapid increases in temperature and is commonly used in large spaces where a single spot detector may not provide adequate coverage. The tubing is filled with air or gas, and when the temperature rises quickly, the air expands, causing a pressure change that triggers the alarm. This design allows for early detection of fires in a wide area, making it an effective choice for certain applications.
15.
Which rate-of-rise heat detector is designed for use in areas normally subject to regular temperature changes that are slower than those under fire conditions?
Correct Answer
B. Rate-compensated detector
Explanation
The rate-compensated detector is designed for use in areas with regular temperature changes that are slower than those under fire conditions. This type of heat detector is able to compensate for these slower temperature changes and accurately detect a rapid rise in temperature that may indicate a fire. It is specifically designed to prevent false alarms caused by normal temperature fluctuations in the environment.
16.
Which rate-of-rise heat detector operates on the principle that when two wires of dissimilar metals are twisted together and heated at one end, and electrical current is generated at the other end?
Correct Answer
A. Thermoelectic Detector
Explanation
A thermoelectric detector operates on the principle of thermoelectric effect, which states that when two wires of dissimilar metals are twisted together and heated at one end, an electrical current is generated at the other end. This current is proportional to the rate of temperature rise, making it a suitable choice for a rate-of-rise heat detector. It can detect rapid temperature changes and trigger an alarm, making it an effective device for fire detection.
17.
Which of the following differences between a smoke detector and a smoke alarm is MOST accurate?
Correct Answer
D. Smoke detectors detect smoke and transmit a signal to an alarm; smoke alarms detect smoke and sound an alarm
Explanation
Smoke detectors are designed to detect smoke and transmit a signal to an alarm system, while smoke alarms are designed to detect smoke and sound an alarm. This means that smoke detectors are typically connected to a larger alarm system that can notify authorities or trigger other safety measures, while smoke alarms are standalone devices that emit a loud noise to alert occupants of a potential fire.
18.
Which smoke detectors use a photoelectric cell coupled with a tiny light source?
Correct Answer
D. pHotoelectric smoke detectors
Explanation
Photoelectric smoke detectors use a photoelectric cell coupled with a tiny light source. This type of smoke detector works by emitting a beam of light into the detection chamber. When smoke particles enter the chamber, they scatter the light, causing it to be detected by the photoelectric cell. This detection triggers the alarm, alerting individuals of a potential fire. Unlike ionization smoke detectors, which use a different method to detect smoke particles, photoelectric smoke detectors are particularly effective at detecting slow-burning, smoldering fires.
19.
Which smoke detectors detect minute particles and aerosols produced during combustion?
Correct Answer
C. Ionization smoke detectors
Explanation
Ionization smoke detectors are designed to detect minute particles and aerosols produced during combustion. They contain a small amount of radioactive material that ionizes the air inside the detector. When smoke enters the detector, it disrupts the ionization process, triggering the alarm. This type of smoke detector is particularly effective at detecting fast, flaming fires.
20.
Which type of photoelectric smoke detector uses a beam of light that focuses across the area being monitored and onto a photoelectric cell?
Correct Answer
B. Beam application
Explanation
A beam application photoelectric smoke detector uses a beam of light that is focused across the area being monitored and onto a photoelectric cell. This type of smoke detector works by emitting a beam of light and measuring the amount of light that is reflected back onto the sensor. When smoke particles enter the monitored area, they scatter the light and cause a decrease in the amount of light reaching the sensor. This change in light intensity triggers the alarm, indicating the presence of smoke.
21.
Which type of photoelectric smoke detector uses a light beam that passes through a small chamber at a point away from the light source?
Correct Answer
C. Refractory application
22.
Ionization smoke detectors use a radioactive material called ____ to ionize air molecules as they enter a chamber within the detector.
Correct Answer
C. Americium
Explanation
Ionization smoke detectors use a radioactive material called Americium to ionize air molecules as they enter a chamber within the detector. Americium is chosen for this purpose because it emits alpha particles, which ionize the air and create an electric current. When smoke enters the chamber, it disrupts the current, triggering the alarm. Cesium, Cadmium, and Technetium are not commonly used in ionization smoke detectors.
23.
Ionization smoke detectors generally respond faster to ___ fires.
Correct Answer
B. Flaming
Explanation
Ionization smoke detectors generally respond faster to flaming fires. This is because flaming fires produce larger smoke particles and higher temperatures, which activate the ionization process in the detector more quickly. The ionization process involves the detection of charged particles in the smoke, and flaming fires produce more of these particles compared to slow or smoldering fires. Therefore, ionization smoke detectors are more effective in detecting and responding to flaming fires.
24.
Batteries in smoke alarms should be changed at least ___ a year.
Correct Answer
B. Twice
Explanation
Smoke alarms are essential for detecting fires and ensuring the safety of a building and its occupants. Therefore, it is crucial to maintain the functionality of these alarms by regularly changing the batteries. The correct answer, "twice," suggests that the batteries in smoke alarms should be replaced at least twice a year. This frequency ensures that the batteries remain fresh and reliable, minimizing the risk of the smoke alarm failing to work when needed.
25.
Which type of smoke alarms are usually more reliable?
Correct Answer
D. Household current
Explanation
Household current smoke alarms are usually more reliable because they are directly connected to the electrical wiring of the house. This means they are less likely to have issues with battery life or malfunctioning batteries, which can be a common problem with ionized, lithium-powered, and battery-operated smoke alarms. Additionally, household current smoke alarms are typically interconnected, meaning that if one alarm detects smoke, it will trigger all the alarms in the house to sound, providing a higher level of safety.
26.
Which detectors are among the most sensitive detectors used to detect fires?
Correct Answer
A. Flame detectors
Explanation
Flame detectors are among the most sensitive detectors used to detect fires. They are specifically designed to detect the presence of flames by sensing the ultraviolet (UV) or infrared (IR) radiation emitted by the flames. This makes them highly effective in quickly detecting fires, even in challenging environments where smoke or other particles may hinder the detection capabilities of other types of detectors. Flame detectors are commonly used in industrial settings, such as oil refineries and chemical plants, where early fire detection is crucial for preventing accidents and minimizing damage.
27.
Which detectors monitor the levels of CO and CO2 in the air?
Correct Answer
B. Fire-gas detectors
Explanation
Fire-gas detectors are the detectors that monitor the levels of CO and CO2 in the air. These detectors are specifically designed to detect the presence of gases produced by fires, such as carbon monoxide (CO) and carbon dioxide (CO2). By monitoring the levels of these gases, fire-gas detectors can provide early warning of a fire and help ensure the safety of occupants in a building. Flame detectors, ionization smoke detectors, and photoelectric detectors are not designed to monitor CO and CO2 levels in the air.
28.
Which detectors are more discriminating than other types?
Correct Answer
B. Fire-gas detectors
Explanation
Fire-gas detectors are more discriminating than other types because they are designed to detect specific gases or combinations of gases that are associated with fires. These detectors can identify the presence of gases such as carbon monoxide, carbon dioxide, methane, and hydrogen, which are indicative of a fire. By detecting these gases, fire-gas detectors can quickly and accurately identify the presence of a fire, allowing for prompt action to be taken. This level of specificity makes fire-gas detectors more discriminating compared to other types of detectors that may only detect general signs of smoke or heat.
29.
Which detectors are prone to being activated by nonfire conditions?
Correct Answer
A. Flame detectors
Explanation
Flame detectors are prone to being activated by nonfire conditions because they are designed to detect the presence of flames, regardless of whether it is a real fire or not. Nonfire conditions such as sunlight, reflections, or other sources of intense heat can trigger the flame detector, leading to false alarms. Therefore, flame detectors require careful placement and calibration to minimize false activations and ensure accurate fire detection.
30.
Which type of flame detectors is insensitive to sunlight?
Correct Answer
B. UV detectors
Explanation
UV detectors are insensitive to sunlight because they operate based on the principle that flames emit UV radiation, while sunlight emits primarily visible and infrared radiation. UV detectors are designed to specifically detect the UV radiation emitted by flames, allowing them to distinguish between flames and other sources of radiation such as sunlight. Therefore, UV detectors are not affected by sunlight and can accurately detect flames even in the presence of sunlight.