Tag: gravitation

Quizzes (12) Questions (21)

Questions Related to gravitation

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

What are known as Spring Tides?

  1. When sun and moon are aligned causes strong high and low tides

  2. When sun and moon are not aligned causes strong high and low tides

  3. When sun and moon are aligned causes only low tides

  4. When sun and moon are not aligned causes only high tides
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tide with the greatest difference between the high and low tide, 

that occurs just after a new or full moon is a spring tide.

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

A stone drop from height 'h' reaches at earth surface in 1 sec. If the some stone taken to moon and drop freely from height h then it will reaches at the surface of moon in the time:

  1. $\sqrt { 6 } sec$

  2. 9 sec
  3. $\sqrt { 3 } sec$

  4. 6 sec
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using h = 0.5 * g * t^2, we have h = 0.5 * g_earth * (1)^2, so h = 0.5 * g_earth. On the moon, g_moon = g_earth / 6. Thus, h = 0.5 * (g_earth / 6) * t_moon^2. Substituting h, we get 0.5 * g_earth = 0.5 * (g_earth / 6) * t_moon^2, so t_moon^2 = 6, t_moon = sqrt(6).