Physics and Applied Physics

Artificial way of causing rainfall to reduce air pollution makes use of

With reference to radioisotope thermoelectric generators (RTGs), consider the following statements: 1. RTGs are miniature fission reactors. 2. RTGs are used for powering the onboard systems of spacecrafts. 3. RTGs can use Plutonium-238, which is a by-product of weapons development. Which of the statements given above are correct?

In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following? 1. Area of the hole in the lid 2. Temperature of the flame 3. Weight of the lid Select the correct answer using the code given below.

With reference to street-lighting, how do sodium lamps differ from LED lamps? 1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps. 2. As street-lights, sodium lamps have longer life span than LED lamps. 3. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street-lighting. Select the correct answer using the code given below.

In the context of modern scientific research, consider the following statements about ‘IceCube’, a particle detector located at South Pole, which was recently in the news : 1. It is the world’s largest neutrino detector, encompassing a cubic kilometre of ice. 2. It is a powerful telescope to search for dark matter. 3. It is buried deep in the ice. Which of the statements given above is/are correct?

During a thunderstorm, the thunder in the skies is produced by the 1. Meeting of cumulonimbus clouds in the sky 2. Lightning that separates the nimbus clouds 3. Violent upward movement of air and water particles Select the correct answer using the codes given below.

Ball bearings are used in bicycles, cars, etc., because

Consider the following phenomena: 1. Size of the sun at dusk 2. Colour of the sun at dawn 3. Moon being visible at dawn 4. Twinkle of stars in the sky 5. Polestar being visible in the sky Which of the above are optical illusions?

Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this? 1. Dispersion 2. Refraction 3. Internal reflection Select the correct answer using the codes given below.

The known forces of nature can be divided into four classes, viz., gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not correct?

The efforts to detect the existence of Higgs boson particle have become frequent news in the recent past. What is/are the importance/ importances of discovering this particle? 1. It will enable us to understand as to why elementary particles have mass. 2. It will enable us in the near future to develop the technology of transferring matter from one point to another without traversing the physical space between them. 3. It will enable us to create better fuels for nuclear fission. Select the correct answer using the codes given below.

A team of scientists at Brookhaven National Laboratory including those from India created the heaviest anti-matter (anti-helium nucleus). What is/are the implication/implications of the creation of anti-matter? 1. It will make mineral prospecting and oil exploration easier and cheaper. 2. It will help probe the possibility of the existence of stars and galaxies made of anti-matter. 3. It will help understand the evolution of the universe. Select the correct answer using the codes given below :

Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth?

Consider the following statements : If there were no phenomenon of capillarity 1. it would be difficult to use a kerosene lamp 2. one would not be able to use a straw to consume a soft drink 3. the blotting paper would fail to function 4. the big trees that we see around would not have grown on the Earth Which of the statements given above are correct?

The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. What is the reason ?

An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth