Tag: elementary ideas of astronomy

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Questions Related to elementary ideas of astronomy

Multiple choice physics gravitation elementary ideas of astronomy shadow formation and optical medium light and shadow

Following factors may be responsible for the colour of a star.
I. The size of the star
II. The distance of the star from the earth
III. The surface temperature of the star
Which combination is correct?

  1. III only

  2. II only

  3. I and II only

  4. I, II and III
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factor responsible for colour of the star is surface temperature of the star it does not depend upon size of the star and distance of star from the earth.

Multiple choice physics gravitation elementary ideas of astronomy shadow formation and optical medium light and shadow

Who is known as father of Modern Indian Astronomy?

  1. Venkoji Bapu Ketkar

  2. Meghnath Saha

  3. M.K. Vainu Bappu

  4. Dr. S. Chandrashekhar
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Manali Kallat Vainu Bappu or M.K Vainu Bappu is known the father of Modern Indian Astronomy. He along with American astronomer Olin Chaddock Wilson discovered the Wilson-Bapu effect in 1957.  

Thus, the correct answer is 'M.K. Vainu Bappu.'

Multiple choice physics gravitation elementary ideas of astronomy shadow formation and optical medium light and shadow

Suppose an earth satellite, revolving in a circular orbit experiences a resistance due to cosmic dust. Then.

  1. Its kinetic energy will increase

  2. Its potential energy will decrease

  3. It will spiral towards the earth and in the process its angular momentum will remain conserved

  4. Both a and b is correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The Kinetic energy of the satellite increases in spiral path as it approach the earth so $V$ must increase the total mechanical energy of the satellite decreases due to resistance from conic dust as satellite approaches earth so potential energy decreases.
Thus Kinetic energy increase potential energy decreases.
Multiple choice physics gravitation elementary ideas of astronomy shadow formation and optical medium light and shadow

The Halley's comet appears after every

  1. $72$ years
  2. $74$ years
  3. $75$ years
  4. $78$ years
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Halley's comet appears after every  $75$ years.

Halley's Comet is arguably the most famous comet. It is a "periodic" comet and returns to Earth's vicinity about every $75$ years, making it possible for a human to see it twice in his or her lifetime. The last time it was here was in 1986, and it is projected to return in $2061.$

The comet is named after English astronomer Edmond Halley, who examined reports of a comet approaching Earth in $1531, 1607$ and $1682$. He concluded that these three comets were actually the same comet returning over and over again, and predicted the comet would come again in $1758$.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

The colour of a green leaf, when white light passing through a yellow filter is applied on it is:

  1. black

  2. yellow

  3. red

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

A yellow filter allows only yellow colour to pass through it. A leaf looks green because leaf reflects green colour and absorbs the rest. Thus, the yellow light passing through the filter will be absorbed by the green leaf. Thus, no colour will be reflected by the leaf making it appear black.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

A beam of light gets reflected from a plane mirror and a real image is formed. The incident beam should be 

  1. Parallel

  2. Convergent

  3. Divergent

  4. Plane mirror cannot form a real image
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  1. Plane mirrors don't usually form real images They form virtual images of real objects. However, things can be arranged so that a plane mirror does form a real image. A convergent light beam can do this. So the answer is "convergent"

  2. When at convergence point, a convergent beam of light is incident on the plane mirror, a real image is formed at the point