Physics · General Awareness

Astrophysics and Cosmology

1,697 Questions

Delve into the mysteries of the universe with questions on black holes, gravitational waves, and spacetime concepts. Topics include the event horizon, the LIGO experiment, and mathematical techniques used in Twistor Theory. These advanced physics concepts are frequently tested in science optional papers.

Black hole physicsGravitational waves and lensingGeneral relativity principlesElectromagnetic spectrum regionsCosmological phenomena

Astrophysics and Cosmology Questions

Multiple choice

Which of the following fits gap (iv)?

Directions: Complete the passage by selecting the most suitable word/phrase from each list to fit the corresponding gap.

Black holes are the (i)______ objects in the Universe. A black hole (ii)_______ have a surface, like a planet or star. Instead, it is a region of space (iii)____ matter has fallen down on itself. This great fall results in a large amount of material packing up (iv)___ a really small area. The pulling force of this region is so great that nothing can escape – not even light.

  1. on

  2. in

  3. at

  4. to
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Correct option is (2).

Multiple choice

The black hole nearest to the Earth named V4641 is visible. How?

  1. Because it is wrongly believed to be a black hole

  2. Because it still has traces of hydrogen

  3. Because of the star that orbits around it

  4. Because of the heat emitted by it
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

At first, scientists believed that the nearest black hole to the Earth was the one at the center of the Milky Way Galaxy. This seemed to be debunked by the discovery of a new black hole only 1600 light years away. This new black hole is actually a rare type of black hole called a micro quasar. This new black hole has been named V4641 Sgr since it is located in the Sagittarius arm of the Milky Way. The reason it is visible is because of the star that orbits it. The gases of this star are steadily being absorbed by this black hole. These gases emit radiation that can be detected by Earth’s telescopes.

Multiple choice lorentz transformation and muon experiment option a: relativity physics
We don't observe space contraction in our every day lives and the reason is

  1. Space contraction is not noticeable until objects approach the speed of light.

  2. Space contraction does not occur until objects approach the speed of light.

  3. Space contraction only occurs in a vacuum.

  4. Space contraction is offset by the effect of gravity.

  5. Acceleration is necessary for length contraction.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The contracted length of objects moving relative to an observer with speed $v$ is given by $l'=l _0\sqrt{1-(\dfrac{v}{c})^2}$.

Hence at small speeds $v<<c$, $l'\approx l _0$, and hence the space contraction is not noticeable.

Multiple choice physics gravitation tides movements of ocean and sea water circulation of ocean water

The type of Gravitational Force that causes tides is known as:

  1. Nuclear Force

  2. Tractive Force

  3. Tidal Force

  4. Wave Force
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Tides are caused by the combined gravitation attraction of the Sun and Moon on the Earth. Force that results in a motion between a body and a tangential surface is called a tractive force.

Multiple choice physics universe and space xx radio telescope and space telescopes optical instruments : telescope

Which among the following is not true for Hubble ST?

  1. Hubbles observations found that black holes are common to the centers of all galaxies.

  2. Hubble's Telescope was first to found the traces of water on Earth.

  3. Hubble Deep field and Hubble Ultra Deep Field images reveal galaxies that are billions of light-years away.

  4. Astronauts used the telescope to observe distant supernovae.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We know that Earth has water, blue planet, 71% of Earth's surface is covered in water. Hubble telescope was definitely not the first to found the traces of water on Earth. 

Multiple choice social science universe and space the big bang and the early development of the universe origin of universe evolution of the universe

The pulses seen from a pulsar are caused by:

  1. gobs of hot gas from an accretion disk falling rhythmically onto the star's surface.

  2. the star's rapid rotation sweeping beams of radiation across the viewer's line of sight.

  3. a dark companion periodically eclipsing the bright ``pulsar' itself.

  4. the star's radius expanding and contracting as it burns iron in its core.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pulsar is a highly magnetized, rotating neutron star. As it rotates, it emits beams of radiation from its magnetic poles; if these beams sweep across Earth, we detect them as periodic pulses.

Multiple choice

Which of the following is NOT true about black holes?

  1. They are formed when a supermassive star collapses

  2. They are found at the center of active galaxies

  3. Scientists can observe them indirectly

  4. They are predicted to occur, but none have been observed
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Black holes have been observed indirectly through their gravitational effects on nearby stars and gas, and the first direct image of a black hole's shadow was captured in 2019.

Multiple choice

What is Stephen Hawking known for?

  1. The theory of everything

  2. Discovering DNA

  3. The physics of black holes

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Stephen Hawking was a theoretical physicist best known for his groundbreaking work on black holes and the singularity theorems. While he wrote a book titled The Theory of Everything, his primary scientific contribution was in the field of black hole physics.

Multiple choice

What can black holes possibly affect?

  1. nothing

  2. the sun

  3. planets

  4. time
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Black holes exert such strong gravity that they warp the fabric of spacetime, effectively slowing down time near the event horizon.

Multiple choice

When do black holes get larger?

  1. they don't

  2. when other stars die near them

  3. when they collide with other black holes

  4. when they get close to other planets
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Black holes increase in mass by accreting surrounding matter or by merging with other black holes.

Multiple choice

What can black holes power be harnessed for?

  1. space travel

  2. time travel

  3. rocket fuel

  4. oil
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Theoretical physics suggests that the immense energy associated with the accretion disks of black holes could potentially be harnessed for advanced propulsion systems in space travel.

Multiple choice

Black holes have the capacity to.......?

  1. destroy the sun

  2. move other stars

  3. distort space

  4. move planets
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Due to their extreme gravitational pull, black holes bend light and warp the geometry of space around them.