Tag: physics

Questions Related to physics

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

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

  1. solar

  2. lunar

  3. either A or B

  4. none of the above

Show answer
Correct Option: B
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.

Eclipse occurs when the Earth, Sun and Moon form:

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

  1. an isosceles triangle

  2. a straight line

  3. any random position

  4. a right angled triangle

Show answer
Correct Option: B
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.

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

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

  1. solar

  2. lunar

  3. either A or B

  4. none of the above

Show answer
Correct Option: A
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.

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?

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

  1. III only

  2. II only

  3. I and II only

  4. I, II and III

Show answer
Correct Option: C
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.

Who is known as father of Modern Indian Astronomy?

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

  1. Venkoji Bapu Ketkar

  2. Meghnath Saha

  3. M.K. Vainu Bappu

  4. Dr. S. Chandrashekhar

Show answer
Correct Option: C
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.'

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

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

  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

Show answer
Correct Option: D
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.

The Halley's comet appears after every

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

  1. $72$ years

  2. $74$ years

  3. $75$ years

  4. $78$ years

Show answer
Correct Option: C
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 $1758$.

Which is the brightest star visible from earth?

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

  1. Sirius

  2. Antares

  3. Vega

  4. Rigel

Show answer
Correct Option: A
Explanation:

The brightest strain the shy is Sirius also known as Dog star or more officially Alpha can is Magon's for its position in constellation canis Major.

What is metrology?

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

  1. The study of people's influx to a metropolitan city

  2. The study of earth's atmosphere

  3. The science of measuring

  4. The study of meteors

Show answer
Correct Option: C
Explanation:

Metrology is the scientific study of the atmosphere that focuseson weather processes and forecasting.

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

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

  1. $100 rpm$

  2. $141 rpm$

  3. $0 rpm$

  4. $200 rpm$

Show answer
Correct Option: D