Cosmic Black Holes IELTS Reading Answers 2026: Answer Key & Explanations

Black Holes Reading Answers: The IELTS Reading test on "Black Holes" includes a variety of question types, such as Matching Sentence Endings, Multiple Choice, and True/False/Not Given. The passage covers key concepts about black holes, their formation, and their role in the universe. It also discusses theories, observations, and the ongoing mysteries surrounding these fascinating cosmic objects. To maximize your preparation, it is recommended to attempt the sample questions within the given 60-minute timeframe. By practicing these questions, students can enhance their understanding of the topic and improve their overall IELTS Reading score.

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Black Holes Reading Answers Passage 

Cosmic Black Hole 

1. In 1687, the English scientist Isaac Newton published his monumental work, Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), containing his theory of gravitation and the mathematics to support it. in essence, Newton's law of gravitation states that the gravitational force between two objects, for example, two astronomical bodies, is directly proportional to their masses. Astronomers found that it accurately predicted all the observable data that science at that time was able to collect, with one exception- a very slight variation in the orbit of the planet Mercury around the sun. 

2. It was 228 years before anyone was able to offer a refinement of Newton's law that accounted for the shape of Mercury's orbit. In 1915, Albert Einstein's general theory of relativity was published. Using the equations of general relativity, he calculated the shape of Mercury's orbit. The results predicted astronomical observations exactly and provided the first proof of his theory. Expressing it very simplistically, the general theory of relativity presumes that both matter and energy can distort space-time and cause it to curve. What we commonly call gravity is in fact the effect of that curvature.

3. Among other phenomena, Einstein's theory predicted the existence of black holes, although initially, he had doubts about their existence. Black holes are areas in space where the gravitational field is so strong that nothing can escape them. Because of the immense gravitational pull, they consume all the light that comes near them, and thus they are black." in fact, neither emitting nor reflecting light, they are invisible. Due to this, they can be studied only by inference based on observations of their effect on the matter- both stars and Gasses- around them and by computer simulation. In particular, when gases are being pulled into a black hole, they can reach temperatures up to 1,000 times the heat of the sun and becomes an intensely glowing source of X rays. 

4. Surrounding each black hole is an "event horizon," which defines the area over which the gravitational force of the black hole operates. Anything passing over the lip of the event horizon is pulled into the black hole. Because observations of event horizons are difficult due to their relatively small size, even less is known about them than about black holes themselves. 

5. Black holes exist in three sizes. Compact ones, called star-mass black holes and which have been known to exist for some time, are believed to be the result of the death of a single star. When a star has consumed itself to the point that it no longer has the energy to support its mass, the core collapses and forms a black hole. Shock waves then bounce out, causing the shell of the star to explode. In a way that is not yet understood, the black hole may then reeneffize and create multiple explosions within the first few minutes of its existence. So-called supermassive black holes, also well documented, contain the mass of millions or even billions of stars. And just recently one intermediate black hole, with about 500 times the mass of the sun, has been discovered. Scientists have postulated that the intermediate black hole may provide a "missing link in understanding the evolution of black holes.

6. Current scientific data suggest that black holes are fairly common and lie at the center of most galaxies. Based on indirect evidence gained using X-ray telescopes, thousands of black holes

7. have been located in our galaxy and beyond. The blagk hole at the center of the Milky Way, known as Sagittarius A* (pronounced "A-star*), is a supermassive one, containing roughly four million times the mass of our sun. Astronomers suggest that orbiting around Sagittarius A*, 26,000 light-years from Earth, maybe as many as tens of thousands of smaller black holes. One possible theory to explain this is that a process called dynamical friction" is causing stellar black holes to sink toward the center of the galaxy. 

8. It is thought that the first black holes came into existence not long after the big bang. Newly created clouds of gases slowly coalesced into the first stars. As these early stars collapsed, they gave rise to the first black holes. A number of theories proposed that the first black holes were essential "seeds," which then gravitationally attracted and consumed enormous quantities of matter found in adjacent gas clouds and dust. This allowed them to grow into the supermassive black holes that now sit in the centers of galaxies. However, a new computer simulation proposes that such growth was minimal. When the simulated star collapsed and formed a black hole, there was very little matter anywhere near the black hole's event horizon. Being in essence "starved," it grew by less than 1 percent over the course of its first hundred million years. The new simulations do not definitively invalidate the seed theory, but they make it far less likely. On the other hand, it is known that black holes existed a billion times more massive than our sun did exist in the early universe. Researchers have yet to discover how these supermassive black holes were formed in such a short time, and the origin of these giants poses one of the most fundamental questions in astrophysics. 

9. It has become practically a hallmark of the research on black holes that with each new study. more is known, more theories are generated, and yet more questions are raised than answered.

Black Holes Reading Answers Sample Questions 

IELTS Matching Sentence Endings (Q. 1-7)

Complete each sentence with the correct ending from the list below (A-G).

1. Newton’s law of gravitation successfully explained planetary motion except for...

2. Einstein’s general theory of relativity showed that gravity is caused by...

3. Black holes are difficult to study directly because they...

4. The event horizon of a black hole marks the boundary where...

5. Star-mass black holes are formed when...

6. The supermassive black hole at the center of the Milky Way is called...

7. Early black holes may have grown by attracting...

List of Endings:
A. curve in space-time caused by matter and energy.
B. are invisible and do not emit light.
C. massive gas clouds and dust.
D. a discrepancy in Mercury’s orbit.
E. dying stars collapse under their own weight.
F. Sagittarius A*.
G. objects cannot escape its gravitational pull.

IELTS Multiple Choice Questions (Q. 8-9)

Choose the correct letter, A, B, C, or D.

8. Why did Einstein doubt the existence of black holes initially?

• A. His equations could not predict them.

• B. There was no direct observational evidence.

• C. Black holes were thought to emit light.

• D. They contradicted Newton’s laws of motion.

9. What was the result of a recent computer simulation on early black holes?

• A. It proved they grew rapidly by consuming nearby matter.

• B. It suggested they did not grow significantly due to a lack of nearby matter.

• C. It confirmed the "seed" theory of black hole formation.

• D. It showed that they vanished quickly after forming.

IELTS True/False/Not Given (Q. 10-13)

Write:

• TRUE if the statement agrees with the information in the passage.

• FALSE if the statement contradicts the information in the passage.

• NOT GIVEN if there is no information on this.

10. Black holes can reflect light under certain conditions.

11. Scientists have discovered thousands of black holes in the Milky Way.

12. The process of "dynamical friction" helps black holes move away from the galaxy’s center.

13. The origin of supermassive black holes remains one of the biggest questions in astrophysics.

Black Holes Reading Answers with Explanations 

1. Newton’s law of gravitation successfully explained planetary motion except for...
   Answer: D. a discrepancy in Mercury’s orbit.
   Location: Paragraph 1 – “Astronomers found that it accurately predicted all the observable data that science at that time was able to collect, with one exception—a very slight variation in the orbit of the planet Mercury around the sun.”
   Explanation: Newton’s law of gravitation worked well but could not fully explain Mercury’s orbit, which was later clarified by Einstein’s theory.

2. Einstein’s general theory of relativity showed that gravity is caused by...
   Answer: A. curve in space-time caused by matter and energy.
   Location: Paragraph 2 – “Expressing it very simplistically, the general theory of relativity presumes that both matter and energy can distort space-time and cause it to curve.”
   Explanation: Einstein’s theory replaced Newton’s gravitational force with the idea that space-time is curved by mass and energy.

3. Black holes are difficult to study directly because they...
   Answer: B. are invisible and do not emit light.
   Location: Paragraph 3 – “Because of the immense gravitational pull, they consume all the light that comes near them, and thus they are ‘black.’ In fact, neither emitting nor reflecting light, they are invisible.”
   Explanation: Since black holes do not emit or reflect light, they can only be studied through indirect methods.

4. The event horizon of a black hole marks the boundary where...
   Answer: G. objects cannot escape its gravitational pull.
   Location: Paragraph 4 – “Surrounding each black hole is an ‘event horizon,’ which defines the area over which the gravitational force of the black hole operates. Anything passing over the lip of the event horizon is pulled into the black hole.”
   Explanation: The event horizon is the point beyond which nothing can escape, making it a defining feature of black holes.

5. Star-mass black holes are formed when...
   Answer: E. dying stars collapse under their own weight.
   Location: Paragraph 5 – “Compact ones, called star-mass black holes and which have been known to exist for some time, are believed to be the result of the death of a single star. When a star has consumed itself to the point that it no longer has the energy to support its mass, the core collapses and forms a black hole.”
   Explanation: Star-mass black holes are created when a dying star collapses due to gravitational forces.

6. The supermassive black hole at the center of the Milky Way is called...
   Answer: F. Sagittarius A*.
   Location: Paragraph 6 – “The black hole at the center of the Milky Way, known as Sagittarius A* (pronounced ‘A-star’), is a supermassive one, containing roughly four million times the mass of our sun.”
   Explanation: The passage explicitly names Sagittarius A* as the black hole in the center of our galaxy.

7. Early black holes may have grown by attracting...
   Answer: C. massive gas clouds and dust.
   Location: Paragraph 7 – “A number of theories proposed that the first black holes were essentially ‘seeds,’ which then gravitationally attracted and consumed enormous quantities of matter found in adjacent gas clouds and dust.”
   Explanation: The passage discusses how early black holes might have grown by pulling in nearby gas and dust.

8. Why did Einstein doubt the existence of black holes initially?
   Answer: B. There was no direct observational evidence.
   Location: Paragraph 3 – “Among other phenomena, Einstein’s theory predicted the existence of black holes, although initially, he had doubts about their existence.”
   Explanation: Einstein’s theory suggested black holes, but he was skeptical because no direct observational evidence existed at the time.

9. What was the result of a recent computer simulation on early black holes?
   Answer: B. It suggested they did not grow significantly due to a lack of nearby matter.
   Location: Paragraph 7 – “However, a new computer simulation proposes that such growth was minimal. When the simulated star collapsed and formed a black hole, there was very little matter anywhere near the black hole’s event horizon. Being in essence ‘starved,’ it grew by less than 1 percent over the course of its first hundred million years.”
   Explanation: The simulation showed that early black holes did not grow significantly due to a lack of surrounding matter.

10. Black holes can reflect light under certain conditions.
    Answer: False
    Location: Paragraph 3 – “Because of the immense gravitational pull, they consume all the light that comes near them, and thus they are ‘black.’ In fact, neither emitting nor reflecting light, they are invisible.”
    Explanation: The passage clearly states that black holes do not emit or reflect light, contradicting the statement.

11. Scientists have discovered thousands of black holes in the Milky Way.
    Answer: True
    Location: Paragraph 6 – “Based on indirect evidence gained using X-ray telescopes, thousands of black holes have been located in our galaxy and beyond.”
    Explanation: The passage confirms that thousands of black holes have been detected using X-ray telescopes.

12. The process of ‘dynamical friction’ helps black holes move away from the galaxy’s center.
    Answer: False
    Location: Paragraph 6 – “One possible theory to explain this is that a process called ‘dynamical friction’ is causing stellar black holes to sink toward the center of the galaxy.”
    Explanation: The statement contradicts the passage, as ‘dynamical friction’ makes black holes move toward the center, not away.

13. The origin of supermassive black holes remains one of the biggest questions in astrophysics.
    Answer: True
    Location: Paragraph 7 – “Researchers have yet to discover how these supermassive black holes were formed in such a short time, and the origin of these giants poses one of the most fundamental questions in astrophysics.”
    Explanation: The passage explicitly states that the formation of supermassive black holes is still an unsolved problem in astrophysics.

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