Consider the following activities:

1. Spraying pesticides on a crop field

2. Inspecting the craters of active volcanoes

3. Collecting breath samples from spouting whales for DNA analysis.

At the present level of technology, which of the above activities can be successfully carried out by using drones?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Ans: d

Explanation:

Drones can be used to spray chemicals like fertilizers, pesticides, etc. based on the spatial variability of the crops and field. The amount of chemicals to be sprayed can be adjusted depending upon the crop conditions, or the degree of severity of the insect-pest attack. In this way, drones pave the pathway to precision agriculture. 

A drone, or unmanned aerial vehicle (UAV), is a remote-controlled device that allows a pilot to remain a safe distance from an active crater while the drone is maneuvered to the site of interest. Drones can be piloted manually or with an autonomous navigation system. Compact gas sensors can be mounted onto the drone that take measurements while the drone is in the air.

The concentrations of carbon dioxide (CO2), sulfur dioxide (SO2), and hydrogen sulfide (H2S) can be measured by flying the drone right into the plume of gas as it emerges from the volcano.

The breath samples provided scientists with DNA and hormone and bacteria measurements. The breath samples provided scientists with DNA and hormone and bacteria measurements

Hence, statements 1, 2, 3 are correct.

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