Free CTS General Technology Test 1 — Questions and Answers
Question 1: Projectors may use different lamp technologies for different reasons. For a long life without changing the light source, which technology is preferred?
- Halogen lamp
- Fluorescent lamp
- LED lamp (Correct answer)
- Arc lamp
Correct answer: LED lamp
LED (Light Emitting Diode) lamps are preferred for long life in projectors because they have significantly longer operational lifespans compared to traditional lamp technologies like halogen or arc lamps. LEDs can last tens of thousands of hours, drastically reducing the need for frequent lamp replacements. This makes them a highly durable and cost-effective choice for sustained use.
Question 2: There is concern about the noise level in an AV rack room. What weight setting on the SPL meter should be used to demonstrate that the noise level doesn't require hearing protection at all times?
- A Weighted (Correct answer)
- C Weighted
- D Weighted
- Z Weighted
Correct answer: A Weighted
A-weighting is a standard filter applied to sound level measurements to approximate the human ear's perception of loudness at different frequencies. It de-emphasizes low and high frequencies, which the human ear is less sensitive to, making it suitable for assessing potential hearing damage or general environmental noise levels. Therefore, A-weighted measurements are used to determine if noise levels are safe for human hearing.
Question 3: Which system is used to show colors from a video display?
- Subtractive color system
- Additive color system (Correct answer)
- Plus/minus color system
- Recover color system
Correct answer: Additive color system
Video displays, such as televisions and computer monitors, use an additive color system to create a wide range of colors. This system mixes varying intensities of red, green, and blue (RGB) light, where combining all three at full intensity produces white light. This is distinct from subtractive color systems used in printing, which start with white and remove colors.
Question 4: The brightness controls on a display adjust which level?
- Black Level (Correct answer)
- Chroma Level
- Hue
- White Level
Correct answer: Black Level
The brightness control on a display primarily adjusts the black level, which determines how dark the darkest parts of the image appear. Adjusting this setting correctly ensures that shadow details are visible without the overall image appearing washed out or overly dark. It sets the baseline for the darkest point in the image, impacting overall contrast.
Question 5: What factors should be addressed while selecting a DC power source for long-distance operation?
- Voltage drop (Correct answer)
- Inductance
- RF interference
- Cable capacitance
Correct answer: Voltage drop
When selecting a DC power source for long-distance operation, voltage drop is a critical factor to address. As current flows through a conductor, resistance causes a reduction in voltage over distance, which can lead to insufficient power reaching the device. Proper cable gauge and voltage must be chosen to minimize this effect and ensure adequate power delivery.
Question 6: What causes Alien Crosstalk (AXT) in network systems?
- Range, reliability, speed, and security
- UTP cables are packaged alongside other low-voltage UTP wires (Correct answer)
- Ensure proper power source(s) and AV program source access.
- Check all ports and check that the screen is not in power saver mode
Correct answer: UTP cables are packaged alongside other low-voltage UTP wires
Alien Crosstalk (AXT) occurs when signals from one unshielded twisted pair (UTP) cable interfere with signals in an adjacent UTP cable, especially when multiple cables are bundled closely together. This interference is external to the cable itself, unlike near-end or far-end crosstalk which occurs within the same cable. Proper cable management and separation are crucial to mitigate AXT.
Question 7: When applying the inverse square law to measurements of sound pressure level:
- A doubling of distance correlates to a loss of 3dB.
- A doubling of distance correlates to a loss of 6dB. (Correct answer)
- A doubling of distance correlates to a gain of 6dB.
- None of the above.
Correct answer: A doubling of distance correlates to a loss of 6dB.
The inverse square law states that for every doubling of the distance from a sound source in a free field, the sound pressure level (SPL) decreases by 6 decibels (dB). This is because the sound energy spreads out over a larger spherical area, reducing its intensity at greater distances. This principle is fundamental in acoustic design and measurement.
Question 8: A common equalizer:
- is one-third octave. (Correct answer)
- is one-half octave.
- operates at mic level.
- can act as a mixer.
Correct answer: is one-third octave.
A common type of graphic equalizer used in professional audio is the one-third octave equalizer. This type allows for precise control over specific frequency bands, as each slider adjusts a frequency range that is one-third of an octave wide. This fine granularity enables detailed shaping of the sound frequency response for optimal audio quality.
Question 9: With light, the amplitude is perceived as:
- Brightness (Correct answer)
- Change of color
- Loss of focus
- Increased pressure
Correct answer: Brightness
In the context of light, amplitude refers to the intensity of the light wave. This intensity is perceived by the human eye as brightness, meaning a higher amplitude corresponds to brighter light, and a lower amplitude corresponds to dimmer light. It directly correlates to how much light energy is being emitted or reflected.
Question 10: Which of the following lists standards for measuring light?
- Candela, Lux, Ohms
- Lux, Nits, Ohms
- Candela, Lux, Nits (Correct answer)
- Candela, Nits, Ohms
Correct answer: Candela, Lux, Nits
Candela, Lux, and Nits are all standard units used for measuring various aspects of light. Candela measures luminous intensity (the power emitted by a light source in a particular direction), Lux measures illuminance (the amount of light falling on a surface), and Nits (cd/m²) measure luminance (the brightness of a surface). These metrics are essential for specifying and evaluating display and lighting performance.
Question 11: Screen gain:
- Is available on electric screens only
- Is the ability of a screen to redirect projected light to the audience to make it appear brighter. (Correct answer)
- Is measured by the foot-angle system
- Is the property of a screen to reject projected light.
Correct answer: Is the ability of a screen to redirect projected light to the audience to make it appear brighter.
Screen gain describes a projection screen's ability to reflect more light back towards the audience than it receives from the projector, making the image appear brighter. A screen with a gain greater than 1.0 concentrates the reflected light into a narrower viewing cone, enhancing perceived brightness for viewers within that cone. This property is crucial for optimizing image visibility in various environments.
Free CTS General Technology Test 1
Projectors may use different lamp technologies for different reasons.
For a long life without changing the light source, which technology is preferred?