54. A silicon sample is doped with 10 15 Arsenic atoms/cm 3 . What is the equilibrium hole concentration P n at 300°K if the intrinsic hole & electron concentration is n i = 1.5 × 10 10 atoms/cm 3 . A. 1.5 × 10 10 cm -3 B. 2.25 × 10 5 cm -3 C. 3.25 × 10 10 cm -3 D. 4.25 × 10 10 cm -3 Answer: Option B Solution n0*p0 = ni^2 Previous yr Question papers with Full Explanations →

53. Following is true for a closed loop op-amp based non-inverting amplifier: (a) It is a voltage shunt feedback amplifier (b) It has its bandwidth under feedback given by B f = (UGB) · K ; K = Attenuation factor           A f by A f = Closed loop gain (c) It has its input resistance under feedback given by R if = R i (1 + AB); R i = input resistance, A = Open loop gain, B = Feedback gain (d) It is a voltage series feedback amplifier A. (a) and (c) only B. (a) and (b) only C. (b) and (d) only D. (c) and (d) only Answer: Option D Previous yr Question papers with Full Explanations →

52. The high frequency and high speed issues of the MOSFET are controlled by the following through the channel: (a) Capacitance charging times (b) Capacitance discharging times (c) Transit time of the carriers (d) Series resistances associated with the source & the drain A. (a) and (b) only B. (a) and (c) only C. (a), (c) and (d) only D. (b) and (d) only Answer: Option B Previous yr Question papers with Full Explanations →

MATLAB Guide: Modeling UVLC Capacity Lower Bounds UVLC Capacity Calculating the point-to-point capacity of an underwater optical link requires modeling Gaussian noise and water attenuation (Beer-Lambert Law). 1. The Capacity Lower Bound Formula C_LB = h(X) + ln(Hc) - f(rho) - h(Y|X) Breaking Down the Symbols This equation is essentially a "Data Budget." You start with a total amount of information and subtract everything that ruins it along the way. h(X) The Volume of your Shout (Input Entropy) This is the total information you are trying to send. A "louder" signal with more variety allows for more data. ln(H c ) The Fog Tax (Channel Loss) Water isn't clear. It absorbs light. This term is a "tax" you pay to the ocean. The murkier the water, the more data you lose here. ...

AI in Telecommunications: Comparing Machine Learning Models for VLC Machine Learning vs. Traditional VLC In the quest for reliable underwater data, researchers are pivoting from simple On-Off Keying (OOK) to advanced Artificial Intelligence . But which model wins? Performance Benchmark: Intelligent-VLC Recent studies show that Intelligent-VLC , an ML-assisted detection system, outperforms traditional methods by nearly 20% in noisy environments. 99.8% Accuracy 0.981 F1-Score 96.1% Precision Comparing the Architectures DC-VLC: Uses Deep Neural Networks to handle signal noise. GOA-VLC: Uses the Grasshopper Optimization Algorithm for dynamic routing. OOK: The legacy standard (Simple but fragile). The conclusion is clear: The integration of feature extraction and intelligent signal detection is the only way to reach 99.9% reliability in turbid harbo...

The Future of 6G: Why UVLC is the Key to the Internet of Underwater Things (IoUT) The Future of 6G: Making the Ocean Transparent How UVLC Technology is building the Internet of Underwater Things (IoUT) Beyond Acoustic: The UVLC Revolution For decades, underwater exploration relied on acoustic signals—slow, high-latency sound waves. As we enter the 6G era, the Internet of Underwater Things (IoUT) demands Gbps-level speeds that sound simply cannot provide. Enter Underwater Visible Light Communication (UVLC) . By utilizing the "Blue-Green Window" (450–550 nm), scientists can now transmit data through water at speeds up to 5 Gbps. Technology Data Rate Latency Range Acoustic ~40 kbps High Kilometers UVLC 1–5 Gbps Ultra-Low ...

5G Antenna Array Response Simulator Antenna Array Response & Beamforming Educational tool for 5G Wireless Communication concepts 1. Array Geometry Number of Elements (N): 8 Steering Angle (\(\theta\)): 90 ° End-fire (0°) Broadside (90°) End-fire (180°) Theoretical Concept As per Figure 2, the extra path distance to reach the next element is \(d \cos\theta\). For \(d = \lambda/2\), the phase shift \(\psi\) between elements is: ...

  Why Transmitted and Received Power are Calculated in dBm What is dBm? dBm means: dB relative to 1 milliwatt (mW) P(dBm) = 10 log₁₀(P(mW)) Examples: Power dBm 1 mW 0 dBm 10 mW 10 dBm 100 mW 20 dBm 1000 mW (1 W) 30 dBm Why Wireless Engineers Use dBm In RF communication, signals experience: Transmitter power Antenna gain Cable loss Free-space path loss Fading losses Using linear watts would require lots of multiplication and division. In dB form: Multiplication becomes addition ...