Day-632 | Daily MCQs | UPSC Prelims | SCIENCE AND TECHNOLOGY

Answer: B
Explanation
Statement 1 is correct: Backpropagation is a fundamental algorithm within neural networks. It is used to optimize the weights of the network by iteratively adjusting them in a direction that minimizes the error between the predicted outputs and the actual outputs of the network.
Statement 2 is correct: Residual Neural Networks (ResNets) did introduce a breakthrough architectural innovation by incorporating skip connections. These connections allow for the training of much deeper networks effectively by mitigating the vanishing gradient problem, enabling the successful training of neural networks with hundreds or even thousands of layers.
Statement 3 is incorrect: Generative Adversarial Networks (GANs) consists of two neural networks, a generator and a discriminator, engaged in a competitive game. The generator aims to produce increasingly realistic samples, while the discriminator learns to distinguish between real and fake samples. Through this adversarial training process, GANs are capable of generating high-quality, realistic data samples, which have applications in image generation, data augmentation, and more.
About Neural Network
A neural network is a computational model inspired by the structure and functioning of biological neural networks in the human brain. It consists of interconnected nodes, called neurons, organized into layers. Each neuron receives input signals, processes them through an activation function, and passes the output to other neurons in the network. Neural networks are capable of learning from data, adjusting their internal parameters (weights and biases) through a process called training. They are widely used in machine learning and artificial intelligence tasks such as classification, regression, pattern recognition, and more.

Answer: B
Explanation
Statement 1 is correct: The piezoelectric effect occurs in certain materials like quartz crystal, where they can generate an electric current when mechanical stress is applied. This effect is widely used in various applications, including sensors, actuators, and energy harvesting devices.
Statement 2 is incorrect: Piezoelectric materials can also exhibit the reverse effect, where they can convert electrical energy into mechanical energy. This property is utilized in devices such as piezoelectric actuators and ultrasonic transducers.
Statement 3 is correct: Recent research has shown that the piezoelectric effect can occur not only in solids but also in certain liquids under specific conditions. The effect has been found in pure 1-butyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide and 1-hexyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide – both ionic liquids This discovery opens up new possibilities for applications in areas such as energy harvesting and sensing in liquid environments.

Answer: A
Explanation
The Yo-Yo test assesses an individual’s aerobic endurance or fitness level, particularly in athletes involved in sports requiring intermittent bursts of high-intensity activity, such as football or soccer. The test involves repeated runs between two points, typically 20 meters apart, with a gradually increasing pace dictated by audio cues. Participants must synchronize their running with the beeps, increasing their speed as the test progresses. The test continues until the participant is unable to maintain the required pace or until exhaustion.
It is primarily used to evaluate an athlete’s ability to perform high-intensity activities over extended periods, measuring parameters such as VO2 max (maximal oxygen consumption), anaerobic threshold, and overall cardiovascular fitness. The Yo-Yo test provides valuable insights into an athlete’s endurance capacity, allowing coaches and trainers to tailor training programs and monitor performance improvements over time.

Answer: A
Explanation
Statement 1 is correct: FLOPS (Floating-Point Operations per Second) is a metric used to measure computational performance. It quantifies the processing power and efficiency of computing systems, especially in high-performance computing and artificial intelligence domains. FLOPs involve mathematical calculations using real numbers with fractional parts. The computing power of today’s supercomputers is often measured in petaFLOPs (PFLOPs), which represent billions or even trillions of operations per second.
Statement 2 is incorrect: Memory bandwidth is the rate at which a processor can read data from or store data into a semiconductor memory. It’s usually expressed in bytes per second, but this can vary for systems with natural data sizes that aren’t a multiple of 8-bit bytes. Memory bandwidth also determines how often values can be accessed from memory.Thus, it is not the maximum memory capacity.

Answer: A
Explanation
Statement 1 is correct: Pulse oximeters are medical devices used to measure the oxygen saturation level in the blood (SpO2) and heart rate. They are commonly used in various healthcare settings, as well as by individuals at home, to monitor respiratory function and overall health.

Statement 2 is incorrect: Pulse oximeters typically utilize infrared light to measure the absorption of oxygenated and deoxygenated hemoglobin in the blood. This is based on the principle of spectrophotometry, where the light absorption characteristics of hemoglobin change with oxygenation levels. Infrared light is commonly used because it penetrates through the skin and is absorbed differently by oxygenated and deoxygenated hemoglobin.