Audio Video Final Reviewer

An RF tuned amplifier is commonly seen because it is widely used in radio frequency applications to amplify and select specific frequencies. It consists of a tuned circuit, which consists of an inductor and a capacitor, that allows only a narrow range of frequencies to pass through and amplifies them. This makes it ideal for applications such as radio receivers and transmitters, where specific frequencies need to be amplified while rejecting others. Additionally, RF tuned amplifiers are commonly used in communication systems, radar systems, and wireless technologies.

Vertical blanking pulses are used to blank out the scanning during the vertical retrace at 60 Hz. During this time, the electron beam in a CRT monitor returns to the top of the screen to begin scanning again. The vertical blanking pulses ensure that the screen is not refreshed during this period, preventing any visual artifacts or flickering. Horizontal sync pulses, on the other hand, are used to synchronize the scanning horizontally. Therefore, the correct answer is vertical blanking pulses.

The term "monochrome" refers to an image or display that uses a single color or shades of a single color, typically black and white. In this context, "luminance without color" can be understood as an image or display that only represents brightness or light intensity without any color information. Therefore, monochrome is the correct answer as it specifically refers to a display or image that lacks color and only represents brightness.

The correct answer is "streaking". Streaking refers to the visual artifact in which horizontal lines or streaks appear on a video display. This can occur when the collector current, which is the current flowing through the collector terminal of a transistor, becomes excessive. When the collector current is too high, it can cause distortions in the video signal, resulting in streaking on the display. Therefore, streaking is the most suitable explanation for the given scenario.

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The correct answer is "E/A standard color bar signal." This answer is chosen because the question is asking about a specific use, which is checking response at high video frequency. Among the given options, the E/A standard color bar signal is the most appropriate choice for this purpose. The other options, such as connecting the base resistor to the collector or Vcc, do not directly relate to checking response at high video frequency.

The correct answer is "virs." VIRS stands for Vertical Interval Reference Signal, which is transmitted on line 19 of the vertical blanking period in both the even and odd fields. It is used to evaluate the performance of the transmission system for chroma and luminance.

Saturation refers to the intensity or purity of a color. It describes how vivid or dull a color appears. Colors with high saturation are vibrant and bold, while colors with low saturation appear more muted or grayish. Saturation is an important concept in fields such as art, design, and photography, as it helps create visual impact and convey emotions.

The question is asking about the brightness for either monochrome information. Out of the given options, "luminance" is the most suitable answer. Luminance refers to the brightness or intensity of light emitted or reflected from a surface. It is commonly used to describe the brightness of monochrome images or displays. Sensitivity, monochrome, and gamma are not directly related to the brightness of monochrome information.

A window signal is a useful tool for checking streaking and ringing in a picture. It consists of a 100 percent white rectangle that is one-half the height and width of the picture, placed on a black background. By analyzing the appearance of the rectangle, one can determine if there are any issues with streaking or ringing in the picture.

The given question is asking for the term that describes the transmission of the modulation sidebands without the subcarrier itself. The correct answer is "suppressed subcarrier" because it refers to the technique of removing or suppressing the subcarrier signal while transmitting only the sidebands in a modulation scheme. This technique is commonly used in certain types of communication systems to conserve bandwidth and improve efficiency.

A composite video signal includes the camera signal along with the picture information, sync pulses, and blanking. This means that it carries both the visual content of the picture as well as the necessary synchronization signals for proper display. The sync pulses ensure that the display device knows when to start and stop displaying each frame, while the blanking signals indicate when the electron beam should be turned off to avoid displaying unnecessary information. Therefore, the composite video signal is the correct answer as it encompasses all the necessary components for a complete video signal.

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The complementary color for blue is yellow. Complementary colors are pairs of colors that when combined, they create a neutral color (such as white or gray). Blue and yellow are opposite each other on the color wheel, making them complementary colors. When blue and yellow are mixed together, they create a neutral gray color.

The D.C Component in a video signal refers to the direct current component that represents the brightness of the background. It indicates the average brightness level of the signal, which helps in determining the overall contrast and brightness of the video. By analyzing the D.C Component, variations in the signal can be detected and adjusted accordingly. The other options mentioned in the question (sensitivity, multiplexer, gamma) are not directly related to indicating the brightness of the background in a video signal.

Gamma is a term used to describe the relationship between the luminance of an image and the digital values used to represent that image. It is a number that indicates how contrast is expanded or compressed. By adjusting the gamma value, the overall brightness and contrast of an image can be modified. A higher gamma value will make the image appear darker and increase contrast, while a lower gamma value will make the image appear brighter and decrease contrast.

The color video signal transmitted as amplitude modulation of the 3.58 MHz c signal is known as the "c signal".

The given answer, "Synchronous modulator," is the correct explanation for the given detector circuit. A synchronous modulator is used with a suppressed carrier signal, which is mentioned in the question. The other options, such as Vc being zero volt, e/a standard color bar signal, and collector current being excessive, do not provide a clear explanation for the detector circuit.

A sub carrier is a carrier wave that is modulated by another carrier wave of higher frequency. It carries the actual information that needs to be transmitted. In this case, the sub carrier wave is being modulated by a carrier wave of higher frequency.

The primary advantage of complementary symmetry in an AF amplifier is that it does not use a transformer. Transformers can introduce losses and distortions in the signal, so by eliminating the need for a transformer, the amplifier can provide a more accurate and efficient amplification of the audio signal. This allows for better sound quality and overall performance of the amplifier.

Cyan is the complementary color for red because complementary colors are those that are opposite each other on the color wheel. Red and cyan are located at opposite ends of the color wheel, making them complementary colors. When red and cyan are combined, they create a neutral gray color.

The occurrence in the picture suggests that there is distortion in the signal. The multiple outlines of edges to the right frequencies indicate that there are unwanted variations or alterations in the waveform, causing distortion. This can be problematic as it puts the amplifier on the brink of oscillations, potentially affecting the quality and accuracy of the signal.

A common base amplifier has a low input impedance, typically around 1k ohms. This means that the input signal is less likely to be attenuated or distorted when connected to the amplifier. Therefore, the given answer, "common base amplifier," is correct in explaining why the input impedance is about 1k ohms.

The given answer, 0.6, indicates that the NPN transistor is made of silicon. This is because silicon transistors typically have a voltage drop of around 0.6 volts when conducting current.

The correct answer is "horizontal sync pulses" because the question is asking about what times the scanning for each line at 15.750. Horizontal sync pulses are used to synchronize the horizontal scanning of a display device, ensuring that each line is scanned at the correct timing. Vertical blanking pulses and vertical sync pulses are related to the vertical scanning of a display device, not the timing of each line. Therefore, the most appropriate answer is horizontal sync pulses.

In a common-emitter configuration, the base current decreases when there is a positive alternation of signal. This is because the input signal causes the base-emitter junction to become forward biased, which in turn reduces the base current. The decrease in base current leads to a decrease in collector current, resulting in amplification of the input signal.

The correct answer is "base resistor is connected to Vcc". In a fixed bias configuration, the base resistor is connected to the positive supply voltage (Vcc). This helps to establish a stable biasing voltage at the base of the transistor, ensuring proper operation. By connecting the base resistor to Vcc, the biasing conditions are set such that the base current increases with an increase in Vcc, providing a stable operating point for the transistor.

This question is asking for the term that describes a combination of the c signal and y luminance signal. The correct answer is "multiplexer". A multiplexer is a device that combines multiple signals into one signal for transmission or processing. In this case, the c signal and y luminance signal are being multiplexed together.

Multiplexing is the process of combining multiple signals into one carrier signal. It allows multiple signals to be transmitted simultaneously over a single communication channel, maximizing the utilization of the channel's capacity. This technique is commonly used in telecommunications and networking to optimize bandwidth usage and improve efficiency in data transmission. Sensitivity refers to the ability of a system to detect or respond to small changes or signals. Multiplexer is a device used in multiplexing to combine multiple signals into one. Window signal is not directly related to the process of combining two signals in one carrier.

The correct answer is that the base emitter junction is shorted. This means that there is a direct connection between the base and emitter terminals of a transistor, causing the voltage reading across this junction to be zero. A shorted base emitter junction can lead to abnormal behavior in the transistor and can affect its overall performance.

Horizontal blanking pulses are responsible for blanking out the retrace for each line in a video signal. These pulses occur at a frequency of 15.750 Hz and ensure that the video signal goes to the black blanking level during the retrace period. This helps to prevent any interference or distortion in the displayed image. Vertical sync pulses, on the other hand, are responsible for synchronizing the vertical refresh rate of the display. Therefore, the correct answer is horizontal blanking pulses.

Emitter bias is the method of biasing a transistor where the base-emitter junction is forward biased and the base-collector junction is reverse biased. This configuration provides stability and allows for better control of the operating point of the transistor. By biasing the emitter, the transistor can be operated in the active region, ensuring proper amplification and minimizing distortion. This biasing method is commonly used in amplifier circuits to achieve optimal performance.

Sensitivity refers to the ability of a receiver to accurately detect and reproduce signals. In the context of the given question, sensitivity is relevant because it determines the ability of both monochrome and color receivers to reproduce a monochrome picture. A high sensitivity receiver will be able to accurately detect and reproduce the y signal, which is used for the black and white picture. Therefore, sensitivity is the correct answer.

When the emitter base-junction of a transistor is shorted, it means that the voltage across the collector (Vc) is zero volts. This is because the shorting of the emitter base-junction causes the transistor to operate in saturation mode, where the collector current is excessive. In saturation mode, the transistor is fully turned on, allowing maximum current flow from the collector to the emitter. As a result, the voltage across the collector (Vc) drops to zero volts.

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Emitter bias is a method of biasing a transistor circuit where the emitter resistor is used to establish the operating point. This method is almost insensitive to temperature variation because the emitter resistor provides negative feedback, which compensates for any changes in temperature. As a result, the biasing point remains stable, ensuring consistent transistor operation regardless of temperature fluctuations.

The correct answer is base current feedback bias. This biasing technique is also known as base current feedback bias. It involves providing a feedback path from the collector to the base of the transistor, which helps stabilize the operating point of the transistor and improve its linearity. This feedback path allows a fraction of the collector current to flow into the base, which helps in compensating for variations in the transistor's parameters and temperature changes.

Voltage divider bias is preferably used to provide a stable circuit operation. In this biasing method, a voltage divider network is used to set the base voltage of the transistor. This ensures that the transistor operates in the desired region, providing stable and consistent circuit operation. The voltage divider bias also helps in maintaining a constant collector current, which further contributes to the stability of the circuit.

The power gain of a common base configuration is high.

Class B amplifiers are a type of amplifier that uses an active device, typically a transistor, to amplify the input signal. In a class B amplifier, the active device conducts for only half of the input signal cycle, allowing for efficient power usage. This means that the active device is not conducting when there is no input signal, reducing power consumption. Therefore, class B amplifiers have an active device.

The transistor is conducting at saturation because the collector current is excessive. In saturation mode, the transistor is fully on and allows maximum current to flow through the collector terminal. This occurs when the base-emitter junction is forward biased and the base-collector junction is reverse biased. The excessive collector current indicates that the transistor is in saturation mode.

The given answer, "the transistor is saturated," is correct because when a transistor is in saturation mode, it means that both the base-emitter junction and the base-collector junction are forward-biased. In this state, the transistor is fully turned on and allows maximum collector current to flow. Therefore, the excessive collector current mentioned in the question suggests that the transistor is saturated.

A ball chart is used with a separate crosshatch generator to check camera linearity independent of the monitor. This means that the ball chart is used to assess the accuracy and consistency of the camera's imaging capabilities without being influenced by the monitor's display. It helps in evaluating the camera's ability to capture and reproduce images accurately, especially in terms of color and contrast.

The correct answer is "input impedance". This is because the question is asking about the factor that is not dependent on the amplifier circuit configuration. The other options (operates at saturation, saturation, and it does not use a transformer) are all specific to certain amplifier circuit configurations and do not apply universally. However, input impedance is a characteristic that can be adjusted or designed independently of the amplifier circuit configuration.

The correct answer is "base resistor is connected to collector." This is because in self-bias configuration, the base resistor is connected to the collector rather than the emitter. This configuration helps in stabilizing the operating point of the transistor and provides a negative feedback that helps in maintaining a constant collector current.

The bias method that is also called collector feedback bias is known as self bias.

In an NPN transistor, the base-emitter junction is forward biased, meaning the base should be positive with respect to the emitter. Therefore, the correct bias for an NPN transistor is that the base should be positive than the emitter.

Voltage divider bias is the method where the operating point is almost stable. In this biasing technique, a voltage divider network is used to set the base voltage of the transistor. This ensures that the transistor operates in the desired region and maintains a stable operating point. By dividing the input voltage, the biasing network provides a stable and constant base voltage, which in turn stabilizes the operating point of the transistor.

The voltage divider bias method is commonly used in switching between saturation. It involves using resistors to create a voltage divider network that biases the base-emitter junction of a transistor. This biasing method ensures that the transistor operates in the desired saturation region, allowing for proper switching behavior.

The best description of base bias is when the base resistor is connected to Vcc. This configuration ensures that the base-emitter junction is forward biased, allowing the transistor to operate in the active region. By connecting the base resistor to Vcc, a stable voltage is provided to the base terminal, which helps maintain the desired operating point and biasing conditions for the transistor. This configuration is commonly used to ensure proper transistor operation and stability in amplifier and switching circuits.