Science & Technology

Biomass gasification is considered to be one of the sustainable solutions to the power crisis in India. In this context, which of the following statements is/are correct? 1. Coconut shells, groundnut shells and rice husk can be used in biomass gasification. 2. The combustible gases generated from biomass gasification consist of hydrogen and carbon dioxide only. 3. The combustible gases generated from biomass gasification can be used for direct heat generation but not in internal combustion engines. Select the correct answer using the codes given below :

What is the role of ultraviolet (UV) radiation in the water purification systems? 1. It inactivates/kills the harmful microorganisms in water. 2. It removes all the undesirable odours from the water. 3. It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of water. Which of the statements given above is/are correct?

Graphene is frequently in news recently. What is its importance? 1. It is a two-dimensional material and has good electrical conductivity. 2. It is one of the thinnest but strongest materials tested so far. 3. It is entirely made of silicon and has high optical transparency. 4. It can be used as 'conducting electrodes' required for touch screens, LCDs and organic LEDs. Which of the statements given above are correct?

With reference to 'stem cells', frequently in the news, which of the following statements is/are correct? 1. Stem cells can be derived from mammals only. 2. Stem cells can be used for screening new drugs. 3. Stem cells can be used for medical therapies. 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 :

Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of universe? 1. Detection of microwaves in space 2. Observation of redshift phenomenon in space 3. Movement of asteroids in space 4. Occurrence of supernova explosions in space 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?

To meet its rapidly growing energy demand, some opine that India should pursue research and development on thorium as the future fuel of nuclear energy. In this context, what advantage does thorium hold over uranium? 1. Thorium is far more abundant in nature than uranium. 2. On the basis of per unit mass of mined mineral, thorium can generate more energy compared to natural uranium. 3. Thorium produces less harmful waste compared to uranium. Which of the statements given above is/are correct?

Which one of the following sets of elements was primarily responsible for the origin of life on the Earth?

Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why? 1. China, which is the largest producer of these elements, has imposed some restrictions on their export. 2. Other than China, Australia, Canada and Chile, these elements are not found in any country. 3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements. Which of the statements given above is/are correct?

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?