Science, Technology & Environment Quiz

Salt lowers the melting point of water through freezing point depression, which is why it's used to melt ice on roads in winter. This physical principle makes salt effective at melting snow and ice at temperatures below water's normal freezing point.

Kolkata houses the first Science City of Asia, established as a major science center and popular science destination. This pioneering institution features interactive exhibits, a space theater, and various scientific demonstrations.

Carbon dioxide fits all the clues: used in carbonated drinks, something people enjoy savoring, essential for photosynthesis in plants, yet harmful in excess in the atmosphere. CO2 is the greenhouse gas that creates this dual nature - beneficial at appropriate levels but damaging when overabundant.

The ozone layer is located in the stratosphere, approximately 15-30 kilometers above Earth's surface. It absorbs harmful ultraviolet (UV) radiation from the sun, protecting living organisms from DNA damage and conditions like skin cancer. The riddle's reference to being 'up above the world' and 'protecting' directly points to this atmospheric layer.

Polar bears are the largest land predators in the Arctic, characterized by their white fur and massive size. They are classified as marine mammals and are threatened by climate change causing sea ice loss. The riddle describing an 'Arctic giant' that is 'furry, huge and white' directly matches the polar bear.

Earth is often referred to as 'Mother Earth' because it has sustained all life since its beginning. The planet provides shelter, resources, and conditions necessary for life. The riddle's imagery of being 'a mother to you all' and 'providing shelter since life started' clearly personifies Earth.

Trees provide essential human needs including oxygen, food, shelter, fuel, and materials. They help combat climate change by absorbing carbon dioxide and prevent soil erosion. Despite these benefits, deforestation continues due to human greed and short-term economic interests.

Greenhouse gases including carbon dioxide, methane, and nitrous oxide trap heat in Earth's atmosphere, causing global warming and climate change. The riddle's reference to 'warming up the climate' directly identifies these gases. They are 'more dangerous than we appear' because they are invisible yet have catastrophic global effects.

When you're the last person leaving a room, you should turn off the light to save energy. 'Turn off the light' is the correct environmental practice. Turning it on would waste energy, and doing nothing defeats the purpose.

Trees are cut down to make paper, causing deforestation. The blank should be 'Trees' - they are 'felled' (cut down) for paper production. Carbon and lead are not felled to make paper; only trees are directly relevant to paper manufacturing.

Plastic bags are environmental hazards - they cause litter, clog drains, choke landfills, and persist in the environment for centuries without degrading. The question advocates avoiding plastic bags for these reasons. Cloth and paper bags are eco-friendly alternatives.

Ultraviolet (UV) rays are used to detect counterfeit currency because many security features fluoresce or become visible only under UV light. These include security threads, watermarks, and invisible ink markings. Alpha and Beta rays are nuclear radiation, and ordinary light rays cannot reveal these hidden security features.

The sky appears blue due to Rayleigh scattering, where shorter blue wavelengths of sunlight are scattered more than longer red wavelengths by molecules and tiny particles in the atmosphere. This scattered blue light reaches our eyes from all directions. Refraction involves bending, and reflection involves bouncing - neither explains the sky's color.

A capacitor stores electrical energy in an electric field between two conductive plates. Resistors limit current flow, inductors store energy in magnetic fields, and conductors simply allow current to pass without storage.

Increased pressure inside a pressure cooker raises the boiling point of water above 100°C. At standard atmospheric pressure, water boils at 100°C, but higher pressure requires higher temperature for boiling.

Polaroid sheets are polarizing filters that block light waves oscillating in specific directions, effectively reducing glare and controlling light intensity. This is why aircraft windows use polarized glass for passenger comfort and visibility.

Simone Giostra is credited with inventing SolPix, a solar-powered LED display system that combines renewable energy with digital art. The other names listed are not associated with this specific invention.

Dr. Martin Cooper invented the first handheld mobile phone at Motorola in 1973, making the first public call from a cellular device. The other scientists listed made contributions in different fields but not mobile telephony.

John Shepherd-Barron invented the ATM in the 1960s, with the first machine installed at Barclays Bank in London. The spacing in his name may be a formatting issue. The other names are not associated with ATM invention.