Tag: physics

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Questions Related to physics

Multiple choice physics light and shadow elementary ideas of astronomy shadow formation and optical medium the solar system nature and sources of light how light travels

When Earth comes in between Sun and Moon and casts its shadow on Moon. The ______ eclipse will occur.

  1. solar

  2. lunar

  3. either A or B

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During lunar eclipse, Earth comes between Sun and Moon in a straight line. The shadow of the Earth falls on the Moon and the Moon gets eclipsed.

Multiple choice physics light and shadow elementary ideas of astronomy shadow formation and optical medium the solar system nature and sources of light how light travels

Eclipse occurs when the Earth, Sun and Moon form:

  1. an isosceles triangle

  2. a straight line

  3. any random position

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

Eclipse occurs when Sun, Earth and Moon come in a straight line. The Earth or Moon that comes in between casts a shadow on Moon or Earth and form lunar or solar eclipse respectively.

Multiple choice physics light and shadow elementary ideas of astronomy shadow formation and optical medium the solar system nature and sources of light how light travels

When the Moon comes in between the Sun and Earth in a straight line, then ________ eclipse will occur.

  1. solar

  2. lunar

  3. either A or B

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During solar eclipse, Moon comes between Sun and the Earth. The Sun is eclipsed where the shadow of the Moon falls on the Earth.

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 light : reflection and refraction from plane surface introduction to light and mirror magic with mirrors image formation by plane mirror principle of reversibility of path of light refractive index

A plane mirror is in a vertical plane and is rotating about a vertical axis at 100 mm horizontal beam of light is incident on the mirror. The reflected beam will rotate at

  1. $100 rpm$

  2. $141 rpm$

  3. $0 rpm$

  4. $200 rpm$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When a mirror rotates at an angular velocity omega, the reflected ray rotates at an angular velocity of 2*omega. Therefore, if the mirror rotates at 100 rpm, the reflected beam rotates at 200 rpm.