Light Year

Q.

Parsec is a unit of

1. Distance

2. Velocity

3. Time

4. Angle

Q.

Light takes $8$ minutes to reach the earth from the sun. Which of the following is correct?

1. Sun is $8$ light years away from the earth

2. Sun is $8$ light minutes away from the earth

3. Sun is one light year away from the earth

4. Sun is 8 light seconds away from the earth

Q.

Why is the distance between stars and planets expressed in light years?

Q.

What do you understand by the statement that a star is 8 light years away from the Earth?

Q.

Define light year. How many kilometres make 1 light year?

Q. Question 15

A star is ten light years away from the earth. Suppose it brightens up suddenly today. After how much time shall we see this change?

Q.

Name the unit which is used to express distances between the various celestial bodies (like stars and planets).

Q.

Our Milky Way galaxy is a ____ type galaxy.

1. Spiral

2. Elliptical

3. Irregular

4. Oval

Q. The units used to measure large distances are:

1. Astronomical unit
2. Light year
3. Candela
4. Lumen

Q.

(a) How much time does light take to reach us from the sun?

(b) How much time does light take to reach us from the next nearest star 'Proxima centauri'?

Q. Match the columns

A	B
(1) Speed of light	(a) 4.3 light years away from earth
(2) Light year	(b) 300, 000 km/s
(3) Sun	(c) Nearest star
(4) Alpha Centauri	(d) distance travelled by light in one year
	(e) 18 light minutes away from the Earth

1. 1-d 2-d, 3-a, 4-e
2. 1-d, 2-b, 3-e, 4-c
3. 1-b, 2-d, 3-c, 4-a
4. 1-a, 2-b, 3-c, 4-e

Q.

How does sound travel as a transverse wave ?

Q.

The distances between the various celestial objects are usually expressed in the unit of:

(a) kilometres

(b) light minutes

(c) light years

(d) light seconds

Q.

Distance travelled by light in one year is called __________.

Q. What is light year?

Q. What do you understand by the statement that a star is eight light years away from the Earth?

1. The distance is equivalent to what earth would travel in eight years.​
2. The distance is equivalent to what light would travel in eight years.
3. The star and earth will meet after eight years.​
4. The distance is equivalent to what star would travel in eight years.​

Q. The Andromeda Galaxy is____________ away from Milky Way.

1. 5.6 million light years
2. 3.5 million light years
3. 2.5 million light years
4. 2 million light years

Q.

Why the ray of sun does not go outside of our galaxy?

Q.

A light year is the unit of distance.

1. True
2. False

Q.

I am sorry to ask my question out of syllabus. My question is:

We know that the universe is expanding rapidly. Every star and planet is going away from one another faster than the speed of light! Then why it is said that our Galaxy (Milky way Galaxy) is coming nearer to our neighbour galaxy (Andromeda Galaxy) and after many years, these galaxies will collide with each other?

Q. Astronomers use light years to measure the speed of light.

1. True
2. False

Q. What will happen if someone fell in a black hole

Q. What is the speed of sound in vacuum?

1. $0m{s}^{-1}$
2. $3\times {10}^{8}m{s}^{-1}$
3. $250m{s}^{-1}$
4. $330m{s}^{-1}$

Q.

why parallax method cannot be used to measure distances of stars more than 100 light years?

Q.

Distance travelled by light in one year is called________.

Q. A new unit of length is chosen such that the speed of light in vaccum is unity.what is the distance between the sun and the earth in the termsof newunit , if light takes 8minutes and 20 seconds to cover this distance?

Q. One light year is the distance that ___ travels in a year.

1. light
2. an astronaut
3. a star
4. earth

Q. The distance of the nearest star besides the sun from the earth is?

1. $4.9\times {10}^{11}$m
2. $9.5\times {10}^{15}$m
3. $2$ light years
4. $4$ light years

Q.

Which of the following are unit(s) of distance?

1. Parsec

2. Wavelength

3. Mile

4. Metre

Q. Suppose a star which is $50$ light years away from Earth explodes today. Will you be able to see the explosion in your lifetime? Give reasons for your lifetime? Give reasons for your answer.