1. Which of the following chemicals causes methaemoglobinaemia?

(a) Nitrates

(b) Sulphates

(c) Carbonates

(d) Phosphates

Answer: (a) Explanation: High nitrate drinking water is associated with Methaemoglobinaemia in which ferrous iron in haemoglobin is oxidized from ferrous to ferric form. MetHb (Methaemoglobin) cannot bind oxygen causing symptoms of cyanosis and drowsiness.

2. In the context of Nitrogen Cycle, Soil Nitrates are transformed into free Nitrogen by which of the following types of bacteria?

(a) Denitrifying bacteria

(b) Nitrifying bacteria

(c) Ammonifying bacteria

(d) None of the above

Answer: (a) Explanation: Denitrifying bacteria are a diverse group of bacteria together with denitrifying fungi and archaea, is capable of performing denitrification as part of the nitrogen cycle. They metabolise nitrogenous compounds using various enzymes, turning nitrogen oxides back to nitrogen gas or nitrous oxide.

Source: https://enviroliteracy.org/air-climate-weather/biogeochemical- cycles/nitrogen-cycle/

3. Which of the following fundamental forces of nature between particles is weakest?

(a) Electromagnetic force

(b) Strong Nuclear force

(c) Weak Nuclear force

(d) Gravitational force

Answer: (d) Explanation: The four fundamental forces of nature are considered to be the gravitational force, the electromagnetic force, which has residual effects, the weak nuclear force, and the strong nuclear force. Each of these forces reacts only on certain particles, and has its own range and force carrier, the particles that transmit the force, by traveling between the affected particles. Gravitational force is the weakest of the four fundamental forces. Ordered from strongest to weakest, the forces are 1) the strong nuclear force, 2) the electromagnetic force, 3) the weak nuclear force, and 4) gravitational force.

Source: http://webhome.phy.duke.edu/~kolena/modern/forces.html

4. With reference to the “National Cyber Coordination Centre (NCCC)", consider the following statements:

(1) It is a multi-stakeholder body and comes under the Indian Computer Emergency Response Team (CERT-In), the Ministry of Electronics and Information Technology.

(2) It derives its powers from the Information Technology Act, 2000.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c) Explanation: Both the given statements are correct. ➢ NCCC is a multi-stakeholder cyber-security and e-surveillance agency ➢ It comes under the Indian Computer Emergency Response Team (CERT-In), Union Ministry of Electronics and Information Technology. ➢ It has powers under the Indian constitution with provision of section 69B of the

Information Technology Act, 2000 ➢ It will be India's first layer for cyber threat monitoring and all communication with the

government as well as the private service providers will be monitored round the clock ➢ Its mandate is to scan internet traffic and communication metadata (which are little snippets of information hidden inside each communication) coming into the country to detect real-time cyber threats.

Source: https://timesofindia.indiatimes.com/india/govt-sets-up-cyber-coordination- centre-to-address-cyber-security-threats/articleshow/63614415.cms http://pib.nic.in/newsite/PrintRelease.aspx?relid=186760

5. The Indian Space Research Organisation (ISRO) is planning to launch the first solar mission, Aditya-L1. Aditya-L1 mission is aimed at studying the Sun from an orbit around the Sun-Earth Lagrangian point 1 (L1). What is Lagrangian Point?

(a) It is a point on outer layers of the Sun, extending to thousands of km above the disc (photosphere) having very high temperature.

(b) It is the point where the combined gravitational force of two large bodies is equal to the centrifugal force that is felt by a third body which is relatively smaller.

(c) It is a point in near Sun at which the solar wind meets the interstellar medium or solar wind from other stars.

(d) A point which is equidistant from the Sun and the Earth.

Answer: (b) Explanation:

• Aditya-L1, India’s maiden mission to the Sun, will be launched in 2019. The main aim of the solar mission is to improve our understanding of “dynamical processes of the sun,” and help resolve some outstanding questions in solar physics.

• The satellite carrying six payloads will be launched from Sriharikota in Andhra Pradesh on the PSLV- XL launch vehicle. It will be launched into the halo orbit around the Lagrangian point 1 (L1) of the Sun-Earth system.

• It is the point where the combined gravitational force of two large bodies is equal to the centrifugal force that is felt by a third body which is relatively smaller.

• This orbit has the advantage of allowing continuous monitoring of the sun. ISRO has over the years led from the front to involve industry from the drawing board to the launch pad as a valued partner in many aspects of our space programme.

Source: https://www.isro.gov.in/aditya-l1-first-indian-mission-to-study-sun