1. Which of the following is/are correct about the Event Horizon Telescope (EHT)?

1. A long-standing goal in astrophysics is to directly observe the immediate environment of a black hole. The ‘event horizon’ is the boundary defining the region of space around a black hole from which nothing can escape.

2. The EHT is an international collaboration to continue the progress in achieving this goal, using the technique of Very Long Baseline interferometry (VLBI) at short wavelengths.

3. In this technique, a network of 8 groundbased radio telescopes have been linked and exploit the rotation of our planet to form one virtual Earth-size telescope observing at a wavelength of 1.3 mm.

Select the correct option from the codes given below:

(a) 1 only

(b) 1 and 2 only

(c) 1, 2 and 3

(d) None of the above

Correct Option: (c)

Explanation:

• A long-standing goal in astrophysics is to directly observe the immediate environment of a black hole.

• The ‘event horizon’ is the boundary defining the region of space around a black hole from which nothing can escape.

• The EHT is an international collaboration to continue the progress in achieving this goal, using the technique of Very Long Baseline interferometry (VLBI) at short wavelengths.

• In this technique, a network of 8 groundbased radio telescopes have been linked and exploit the rotation of our planet to form one virtual Earth-size telescope observing at a wavelength of 1.3 mm.

2. Consider the following statements:

1. Black holes were predicted by Einstein’s theory of general relativity.

2. Black holes can be directly observed because they do not emit or radiate light, or any other electromagnetic waves that can be detected by instruments built by human beings.

Which of the following is/are incorrect?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Correct Option: (b)

Explanation:

Black holes

• Black holes can be directly observed because they do not emit or radiate light, or any other electromagnetic waves that can be detected by instruments built by human beings.

3. Which of the following is/are correct about Chandrayaan-2?

1. It is ISRO’s first interplanetary mission to land a rover on any celestial body.

2. It was launched by Geosynchronous Satellite Launch Vehicle Mk III (GSLVF10).

3. Only four countries have ever softlanded on the moon— France, the United States, the U.S.S.R., and China.

Select the correct option from the codes given below:

(a) 1 and 2 only

(b) 1, 2 and 3

(c) 2 only

(d) 3 only

Correct Option: (a)

Explanation:

Chandrayaan-2

• It is ISRO’s first interplanetary mission to land a rover on any celestial body.

• It was launched by Geosynchronous Satellite Launch Vehicle Mk III (GSLVF10).

• Only 3 countries have ever soft-landed on the moon— the United States, the U.S.S.R., and China.

4. Which is the first molecule to be formed in our universe for the first time?

(a) Sodium hydride

(b) Calcium hydride

(c) Potassium hydride

(d) Helium hydride

Correct Option: (d)

Explanation:

First molecule of the universe

• Helium hydride is the first molecule to be formed in our universe for the first time.

5. Mosquirix is a vaccine developed to treat which of the following?

(a) SARS

(b) MERS

(c) COVID-19

(d) Malaria

Correct Option: (d)

Explanation:

Mosquirix

• Mosquirix is a vaccine developed to treat Malaria.