Fuels And Forces: A Quiz On Sources Of Energy

In a hydroelectric power plant, electrical power can be generated by converting the potential energy of falling water into kinetic energy, which then drives a turbine to generate electricity. The greater the height from which the water falls, the larger the amount of potential energy available. Therefore, a larger amount of potential energy can be converted into kinetic energy when the water falls from a greater height, resulting in the generation of more electrical power.

CFL stands for Compact Fluorescent Lamp, which is an energy-efficient device for producing light. CFLs use less energy compared to traditional incandescent bulbs, making them more environmentally friendly and cost-effective. They produce the same amount of light but consume less electricity, resulting in lower energy bills and reduced carbon emissions. CFLs also have a longer lifespan, lasting up to 10 times longer than incandescent bulbs. Therefore, CFL is the correct answer as it is a widely used energy-efficient lighting option.

The disposal of wastes produced in a nuclear power plant poses a big problem because they are highly radioactive. Radioactive waste contains substances that emit harmful ionizing radiation, which can cause severe health and environmental hazards if not properly managed. The high radioactivity of these wastes necessitates careful handling, storage, and disposal to prevent contamination and exposure to humans and the environment.

The cover of the solar cooker should be made of a transparent material in order to allow sunlight to pass through and heat up the cooker. Transparent glass sheet is the best option as it is durable, allows maximum sunlight to enter, and provides insulation to retain heat inside the cooker. Transparent plastic sheet may not be as durable or insulating, while shining aluminium sheet would reflect sunlight instead of allowing it to pass through. Butter paper sheet may not be transparent enough to allow sufficient sunlight to enter the cooker.

The rise of sea-water during high tide is caused by the gravitational pull of the Moon. The Moon's gravitational force attracts the water on Earth's surface, causing it to bulge and create a high tide. This gravitational pull is stronger on the side of the Earth facing the Moon, creating a high tide, and weaker on the opposite side, creating a low tide. The Sun also has an effect on tides, but its gravitational pull is less significant compared to the Moon's.

Charcoal is the correct answer because it is commonly used as a fuel for barbecues. It is lightweight, easy to ignite, and produces a high heat output, making it ideal for grilling food. Charcoal is made by heating wood in the absence of oxygen, which removes moisture and impurities, leaving behind a carbon-rich material that burns efficiently. It is a popular choice for barbecues due to its ability to provide a consistent and long-lasting heat source, resulting in deliciously cooked food with a smoky flavor.

The fuel with the highest calorific value will have less carbon but more hydrogen. This is because hydrogen has a higher energy content per unit mass compared to carbon. So, a fuel with more hydrogen will release more energy when burned, resulting in a higher calorific value.

The radiation in sunlight that gives us the feeling of hotness is infra-red. Infra-red radiation has longer wavelengths than visible light, and it is responsible for the heat that we feel from the sun. This type of radiation is not visible to the human eye, but it can be detected as heat. Ultra-violet radiation, on the other hand, is responsible for sunburn and is not associated with the feeling of hotness.

A good fuel should have a high calorific value, which means it can produce a large amount of heat energy when burned. This makes it more efficient and cost-effective. Additionally, a fuel with a moderate ignition temperature is desirable as it ensures that the fuel can be easily ignited without requiring excessive heat or energy. This makes it safer and easier to use. Therefore, a fuel with high calorific value and moderate ignition temperature is considered to be a good fuel.

The solar constant represents the amount of solar energy that reaches the Earth's atmosphere per unit area. It is given as 1.4 kW/m2. To calculate the solar energy received by 1 m2 area in one hour, we need to convert the solar constant from kW to J and multiply it by the time in seconds. Since 1 kW = 1000 J/s, the solar constant is equal to 1.4 * 1000 J/s = 1400 J/s. Multiplying this by 3600 seconds (1 hour) gives us 5040 kJ, which is the correct answer.

Coke is more valuable as a reducing agent because it has the ability to remove oxygen from a substance during a chemical reaction. This property makes it useful in various industrial processes, such as the production of metals from their ores. By acting as a reducing agent, coke helps to extract metals by reducing their oxides to the pure metal form. This makes coke an important component in industries that rely on the reduction of substances.

One atomic mass unit (u) is equivalent to an energy of 931 MeV. This is because the conversion factor between mass and energy is given by Einstein's famous equation, E=mc^2, where E is energy, m is mass, and c is the speed of light. In this case, the mass is 1 atomic mass unit (u), and when multiplied by the square of the speed of light (c^2), it gives an energy of 931 MeV.

The energy produced by converting 1 gram mass of nuclear fuel into energy completely is 9 × 10^13 J.

Stage 2 in the process of producing electricity involves making steam flow fast. This is typically achieved by heating water to produce steam and then directing the steam at high velocity through a turbine. The high-speed steam causes the turbine to rotate, which in turn drives a generator to produce electricity.

The efficiency of a fuel can be determined by calculating the energy released per unit mass. In this case, the energy released is proportional to the temperature rise of the water. The fuel that has the lowest temperature rise for a given mass of fuel burned is the least efficient in terms of energy released per unit mass. Therefore, fuel A, which has a temperature rise of 12oC for a mass of 0.80g, is the least efficient fuel.