1.
SPC stands
Correct Answer
B. Stored Program Control
Explanation
Stored Program Control (SPC) refers to a method of controlling telecommunications systems where the control functions are performed by a computer program stored in memory. In this system, the program controls the switching functions, call routing, and other operations of the telecommunications system. This allows for more efficient and flexible control over the system, as changes can be made by updating the program rather than physically rewiring the system. SPC is commonly used in telephone exchanges and other telecommunications networks.
2.
For two-stage network, the switching elements for M inlets with r blocks and N outlets with s blocks are given by
Correct Answer
A. Ms + Nr
Explanation
The given expression, Ms + Nr, represents the number of switching elements required for a two-stage network with M inlets and N outlets. In the first stage, there are M inlets and r blocks, so the number of switching elements required is Mr. In the second stage, there are N outlets and s blocks, so the number of switching elements required is Ns. Therefore, the total number of switching elements required for the two-stage network is Ms + Nr.
3.
As per Nyquist criterion, the sampling rate is:
Where fs is the signal frequency
Correct Answer
A. 2fs
Explanation
As per Nyquist criterion, the sampling rate should be at least twice the signal frequency (2fs) in order to accurately reconstruct the original signal. This is because the Nyquist-Shannon sampling theorem states that in order to avoid aliasing and loss of information, the sampling rate must be greater than or equal to twice the highest frequency component of the signal being sampled. Therefore, the correct answer is 2fs.
4.
To receive satellite signal feed is kept at ________________ of PDA.
Correct Answer
Focal Point
Explanation
The correct answer is "Focal Point." The focal point is the specific point where all the parallel rays of light converge after passing through a lens or reflecting off a mirror. In the context of receiving a satellite signal feed, the focal point refers to the point where the feed is focused and concentrated to ensure optimal reception. By keeping the feed at the focal point of a PDA (Personal Digital Assistant), the device can effectively capture and process the satellite signal.
5.
Peak to peak value of an a.c. voltage can be measured with the help of ____________________
Correct Answer
CRO
Explanation
The peak to peak value of an AC voltage can be measured with the help of a CRO, which stands for Cathode Ray Oscilloscope. A CRO is a device used to display and analyze electrical waveforms. It works by using a beam of electrons that is deflected by the voltage being measured, creating a visual representation on a screen. By observing the waveform on the screen, the peak to peak value of the AC voltage can be determined by measuring the vertical distance between the highest and lowest points of the waveform.
6.
Type of modulation used in visual section of a transmitter.
Correct Answer
B. Negative A.M
Explanation
Negative A.M. stands for Negative Amplitude Modulation, which is a type of modulation used in the visual section of a transmitter. In this type of modulation, the amplitude of the carrier signal is varied in such a way that it is inversely proportional to the amplitude of the modulating signal. This means that as the modulating signal increases in amplitude, the carrier signal decreases in amplitude, and vice versa. Negative A.M. is commonly used in television broadcasting to transmit video signals, as it allows for the transmission of both positive and negative-going video signals.
7.
The Difference between video I.F. & audio I. F in TV transmitter is
Correct Answer
C. 5.50 MHz
Explanation
The correct answer is 5.50 MHz. In a TV transmitter, the video intermediate frequency (I.F.) and audio I.F. are different frequencies used to transmit the video and audio signals respectively. The difference between these two frequencies is 5.50 MHz.
8.
Duration of vertical blanking is
Correct Answer
C. 1.6 milli second
Explanation
The duration of vertical blanking refers to the time interval during which the electron beam in a CRT (Cathode Ray Tube) television or monitor returns to the top of the screen after displaying the last line of the image. This blanking period allows for repositioning and refreshing of the electron beam. The correct answer, 1.6 millisecond, indicates that the vertical blanking lasts for 1.6 milliseconds.
9.
Duration of horizontal sync pulse is
Correct Answer
C. 3. 4.7 micro second
Explanation
The duration of the horizontal sync pulse refers to the time it takes for the horizontal synchronization signal to be transmitted. In this case, the correct answer is 3. 4.7 microseconds, as it indicates that the synchronization signal lasts for 4.7 microseconds.
10.
I.F. at output of TV Receiver tuner for video is
Correct Answer
A. 38.9 MHz
Explanation
The correct answer is 38.9 MHz. This is the frequency at which the TV Receiver tuner outputs the video signal.
11.
A slotted antenna is used for
Correct Answer
B. UHF
Explanation
A slotted antenna is used for UHF frequencies because it is specifically designed to operate efficiently in the UHF range. The slots in the antenna allow for better transmission and reception of UHF signals, as they are designed to match the wavelength of UHF frequencies. VHF frequencies require a different type of antenna to operate effectively, so a slotted antenna would not be suitable for VHF. Therefore, the correct answer is UHF.
12.
The PDA used for TVRO is used for
Correct Answer
A. Receiving signals
Explanation
The PDA used for TVRO is primarily used for receiving signals. It is designed to capture and decode satellite signals to provide television programming. While it is possible for some PDAs to also transmit signals, the main purpose of a TVRO PDA is to receive signals rather than transmit them. Therefore, the correct answer is "Receiving signals."
13.
Three Primary Colours in TV Transmission are
Correct Answer
A. Red, Green, Blue
Explanation
The three primary colors in TV transmission are red, green, and blue. These colors are used because they can be combined in different intensities to create a wide range of colors that our eyes can perceive. By mixing different amounts of red, green, and blue light, all the colors visible on a TV screen can be produced. This is known as the RGB color model, which is widely used in electronic displays including televisions.
14.
Colour Temperature of average day light is
Correct Answer
C. 6500 K
Explanation
The correct answer is 6500 K. The color temperature of average daylight is typically around 6500 K. This refers to the color appearance of the light, with lower values indicating warmer, more yellowish light and higher values indicating cooler, bluish light. 6500 K is considered a neutral white light, similar to the color temperature of a clear blue sky.
15.
Eye is more sensitive to
Correct Answer
B. Green
Explanation
The eye is more sensitive to green because the human eye contains more green receptors, known as cones, compared to red and blue receptors. These cones are responsible for detecting and processing different colors of light. The higher sensitivity to green light allows us to perceive green colors more accurately and distinguish various shades of green.