Question : Out of the following sports, in which friction plays the least important role?
Option 1: Football
Option 2: Hockey
Option 3: Basketball
Option 4: Ice skating
Correct Answer: Basketball
Solution : Firstly, the roughness or irregularities of surface, and secondly, the strong atomic or muscular forces of attraction between the two surfaces at the points of actual contact. Types of friction: Static and Dynamic.
Question : Identify the correct statement about gravity.
Option 1: The unit of g is the same as that of velocity.
Option 2: The unit of g is the same as that of friction.
Option 3: The unit of g is the same as that of mass.
Option 4: The unit of g is the same as that of acceleration.
Question : Read the passage and answer the following questions. IIT Delhi researchers have designed and fabricated a device that can generate electricity from water drops, raindrops, water streams, and even from ocean waves using "Triboelectric Effect" and "Electrostatic Induction". The device is called "Liquid-solid Interface Triboelectric Nanogenerator". The generated electricity can be stored in batteries for further use. Triboelectric effect is a known phenomenon for a long time, and in this effect, charges are generated when two surfaces are in friction. The best example we see are sparkling lights when we move the blankets/jackets.
The device has a very simple structure consisting of specially designed nanocomposite polymers and contact electrodes and can generate a few Milliwatt mW power, which is sufficient to power small electronic devices like watches, digital thermometers, radio frequency transmitters, healthcare sensors, pedometers. When compared to conventional methods, such as the use of the piezoelectric effect, the present device can generate significantly more electricity.
The researchers successfully incorporated nanostructures into a polymer matrix, which enhanced the film's surface roughness, polarizability, and hydrophobicity, among other characteristics, as a result. Due to the enhancement in the above property, the flexible film is used to fabricate the device where raindrops have just to slide down and can generate electricity. The artificially created rough surface allows to generate more charge and superhydrophobic properties of the solid surface help to roll the water drop without getting stick to the surface.
The IIT Delhi research team also explored the underlying mechanism of the electricity generated when the water drop comes in contact with the solid surface and it is shown that saline water drops generate more electricity. The researchers also showed that the device can even work with ocean waves, where the water is saline, and through the ocean waves contacting the surface of nanocomposite polymer film, electricity is generated.
Question:Name the electronic devices which can be powered with the device mentioned in the passage: 1. Watches 2. Pedometers 3. Refrigerators 4. Radio Frequency Transmitters
Option 1: Only 1 and 2
Option 2: All 1,2,3, and 4
Option 3: Only 3 and 4
Option 4: Only 1,2 , and 4
Question : Comprehension: Read the given passage and answer the questions that follow. Difficult times could create feelings of anxiety, insecurity, and fear. As we navigate through undesirable situations and uncertainties, we find that the negativity surrounding the problems consumes our minds. It is in those times that we have to exert ourselves to change our perspective and adopt a more positive and solution-driven attitude. Wise people have always chosen to leverage adversities as opportunities for growth and progress rather than succumb to negative thought patterns. Saint Kabir described how different people respond when challenged by problems: "Gold, virtuous people, and saints are resilient; you may break them a hundred times and yet they will re-join. In contrast, negative people and clay pots are fragile; once shattered, they are broken forever." The distinguishing feature of the successful is that they have a mindset that enables them to remain positive in the face of adversity and even utilise the negative situation for their benefit. The eagle can teach us a few lessons on this. When the storm starts blowing, it does not cower down before it. It flies to a higher point and waits for the wind to blow over. When the storm sets in, the eagle spreads its wings and uses the draft of the wind to rise higher and higher in the sky. It does not run away from the storm; rather, it uses the storm to its advantage. While the storm rages below, the eagle soars above it. The winning attitude to overcome despair and stress is to realise that adversities have opportunities inherent in them, and opportunities do not come without problems. Hence, difficulties and obstacles have a positive side to them as they make us grow from within. A gem gets polished with friction. The finest steel is produced by putting it on fire. Similarly, the more hardships we face, the stronger we become.
Question: Which of the following is an ideal way of handling a difficult situation?
Option 1: Thinking deeply about the impact of adversities
Option 2: Moving away from difficulties
Option 3: Making the best use of a situation to your advantage
Option 4: Becoming overcome by stress and negativity
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