6: Assertion (A) :
Activated charcoal is used for decolourising sugar solution.
Reason (R) :
Activated charcoal absorbs the impurities on its surface.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
7: India-based Neutrino Observatory is included by the Planning Commission as a mega science project under the 11th five-Year Plan. In this context, consider the following statements:
1. Neutrinos are chargeless elementary particles that travel close to the speed of light.
2. Neutrinos are created in nuclear reactions of beta decay.
3. Neutrinos have a negligible, but nonzero mass.
4. Trillions of Neutrinos pass through human body every second.
Which of the statements given above are correct ?
(a) 1 and 3 only
(b) 1, 2 and 3 only
(c) 2, 3 and 4
(d) 1, 2, 3 and 4
Explanation:
A neutrino is an elementary particle that usually travels close to the speed of light, is electrically neutral, and is able to pass through ordinary matter almost undisturbed. This makes neutrinos extremely difficult to detect. Neutrinos have a very small, but nonzero mass.
Neutrinos are created as a result of certain types of radioactive decay or nuclear reactions such as those that take place in the sun, in nuclear reactors, or when cosmic rays hit atoms. There are three types, or "flavours", of neutrinos. Electron neutrinos (or antineutrinos) are generated whenever protons change into neutrons (or vice versa), the two forms of beta decay. Interactions involving neutrinos are mediated by the weak interaction.
Most neutrinos passing through the Earth emanate from the Sun, and more than 50 trillion solar neutrinos pass through the human body every second.
Indira-based Neutrino Observatory (INO) is a proposed particle physics research project to primarily study atmospheric neutrinos in a 1,300 meters (4,265 ft) deep cave under Ino Peak near Masinagudi, Tamil Nadu, India. This project is notable in that it is anticipated to provide a precise of measurement of neutrino mixing parameters. But in November 2009, the Ministry of Environment (India), denied permission for the Department of Atomic Energy (India) to set up the India-based Neutrino Observatory (INO) project at Singara.
8: Which one of the following statements is not correct ?
(a) All echinoderms are viviparous
(b) Round worm has no circulatory system
(c) In bony fishes, swim bladder is usually present
(d) In cartilaginous fishes, fertilisation is internal
10: Consider the following:
1. Photosynthesis
2. Respiration
3. Decay of organic matter
4. Volcanic action
Which of the above add carbon dioxide to the carbon cycle on Earth
(a) 1 and 4 only
(b) 2 and 3 only
(c) 2, 3 and 4 only
(d) 1, 2, 3 and 4
Explanation:
Photosynthesis and respiration are essentially the opposite of one another. Photosynthesis removes CO2 from the atmosphere and replaces it with O2. Respiration takes O2.
The combustion of fossil fuels mainly adds carbon dioxide to air, some of it is also released during natural processes, such as volcanic eruptions.