Ans: B

Exp:

The time required to identify those individuals who have received a significant dose of radiation is crucial as treatments for radiation are more effective the earlier they are administered, as per a study.

About Biodosimetry:

• It  is a method used to estimate the amount of radiation a person has been exposed to.

• Purpose: Determine radiation exposure based on biological changes.
• Biological Samples Used: Blood, urine, hair.
• Application: Particularly useful in radiological events without personal radiation monitoring devices.

Hence, option B is correct.

Ans: C

Exp: 

Earth reaches aphelion on 5th July.

About Aphelion:

• The word aphelion is derived from the Greek words apo, which means away or apart, and helios, which is the Greek God of the Sun. Therefore, aphelion means “apart from the Sun”.
• Statement 1 is correct:At aphelion, Earth’s distance from the Sun is about 152.1 million km.
• Statement 2 is correct:Six months later, in early January, Earth reaches perihelion — the point at which it is closest to the Sun. 
  • At perihelion, the distance between Earth and the Sun is roughly 147.1 million km (see illustration).

Ans: D

Exp:

• Recently, the Defence Ministry has implemented Velmenni’s Li-Fi technology to address communication challenges within the Indian Navy.

About Li-Fi technology:

• Statement 2 correct:LiFi (Light Fidelity) is a wireless communication technology that utilises visible light, particularly LED bulbs, for data transmission.

• Statement 3  correct:It was Invented by Professor Harald Haas in 2011, LiFi provides high-speed, bidirectional mobile communication similar to WiFi, offering faster speeds, reduced latency, and increased bandwidth (thousands of terahertz).

• Statement 1 correct: Li-Fi utilises LEDs, commonly used for lighting, to transmit information. These LEDs can be rapidly modulated to encode data. When an electrical signal is sent to an LED, it emits light. By varying the intensity of this light rapidly, information can be transmitted.

Ans: C

Exp: 

Catania airport on the Italian island of Sicily was closed recently, after Mount Etna, the largest active volcano in Europe erupted.

About  Mount Etna:

• Statement 1 correct: Mount Etna is on the east coast of Sicily, (Italy) which is the largest island in the Mediterranean Sea. 

• Its strategic location influences both local climate and agricultural practices due to its volcanic ash contributing to fertile soil.

• The summit of Mount Etna features five main craters which are the primary sources of its frequent eruptions. 

• Additionally, the mountain is dotted with over 300 vents that vary in size. These vents are scattered along its slopes and contribute to both summit and flank eruptions.

• Statement 2 correct: Mount Etna has been designated a World Heritage Site since 2013. According to UNESCO, the volcano’s eruptive history can be traced back 500,000 years, out of which 2,700 years of this activity has been documented.

Ans: C

Exp: 

Recently, the African Swine Fever outbreak was reported in Kerala’s Thrissur district.

About ‘African swine fever (ASF):

• Statement 1 correct: African swine fever (ASF) is a highly contagious and hemorrhagic viral disease of domestic and wild pigs. 
• It is a notifiable disease and its outbreak should be immediately reported to the higher authorities. ASF causes a destructive effect on piggery due to high morbidity and mortality (up to 90-100 %). In India it was first confirmed in Arunachal Pradesh and Assam in February-March 2020. 

Statement 2 correct: Currently, there is no effective vaccine available against ASF, so prevention by adopting strict biosecurity measures is the only way to prevent ASF.