‘Aerial metagenomics’ best refers to which one of the following situations?

[UPSC CSE 2023] #Science #Technology

(a) Collecting DNA samples from air in a habitat at one go.

(b) Understanding the genetic makeup of avian species of a habitat.

(c) Using air-borne devices to collect blood samples from moving animals.

(d) Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies.

With reference to green hydrogen, consider the following statements:

[UPSC CSE 2023] #Science #Technology

1. It can be used directly as a fuel for internal combustion.

2. It can be blended with natural gas and used as fuel for heat or power generation.

3. It can be used in the hydrogen fuel cell to run vehicles.

How many of the above statements are correct?

Consider the following statements :

[UPSC CSE 2023] #Science #Technology

1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket-powered only in the initial phase of flight.

2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.

Which of the statements given above are correct?

Consider the following statements regarding mercury pollution :

[UPSC CSE 2023] #Science #Technology

1. Gold mining activity is a source of mercury pollution in the world.

2. Coal-based thermal power plants cause mercury pollution.

3. There is no known safe level of exposure to mercury.

How many of the above statements are correct?

With reference to the role of biofilters in Recirculating Aquaculture System consider the following statements :

[UPSC CSE 2023] #Science #Technology

1. Biofilters provide waste treatment by removing uneaten fish feed.

2. Biofilters convert ammonia present in fish waste to nitrate.

3. Biofilters increase phosphorus as nutrient for fish in water

How many of the statements given above are correct?

Consider the following Pairs:

[UPSC CSE 2023] #Science #Technology

Objects in space : Description

1. Cepheids : Giant clouds of dust and gas in space

2. Nebulae : Stars which brighten and dim periodically

3. Pulsars : Neutron stars that are formed when massive stars run out of fuel and collapse

How many of the above pairs are correctly matched?

Consider the following statements :

[UPSC CSE 2023] #Science #Technology

1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts.

2. Carbon fibres once used cannot be recycled.

Which one of the statements given above is/are correct?

Consider the following statements :

[UPSC CSE 2023] #Science #Technology

1. Detection of car crash collision which results in the deployment of airbags almost instantaneously

2. Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive.

3. Detection of the tilt of the smartphone which results in the rotation of display between portrait and landscape mode.

In how many of the above actions is the functions of accelerometer required?

Assertion A: When an artificial satellite moves around the earth in a circular orbit with a constant speed, its velocity is not constant because the direction of motion of the satellite is changing continuously.

Reason R: The force of gravity of earth keeps the satellite in circular orbit around it.

[HCS 2023] #Science #Technology

In the light of the above statements, choose the correct answer from the options given below:

With reference to "PraVaHa" software developed by ISRO, which of the following statements is/are correct?

[UPPCS 2024] #Science #Technology #CA

1. It is a path-breaking feat by Vikram Sarabhai Space Centre.

2. Initial aerodynamic design of space vehicles requires evaluation of a large number of configurations.

Select the correct answer from the codes given below:

Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R):

[UPPCS 2024] #Science #Technology #CA

Assertion (A): In April 2024, India delivered the BrahMos Supersonic Cruise Missile to Philippines.

Reason (R): The Missile has a range of 490 kilometres.

Select the correct answer from the codes given below: