Tag: india’s space programmes

Questions Related to india’s space programmes

Communication satellites move in orbits of radius 44,400 km around the earth find the acceleration of such a satelite, assuming that the only force acting on, it is that  due to the earth.Mass of the earth $ = 6 \times {10^{24}}Kg.$

  1. $0.2\;m{s^{ - 2}}$

  2. $2.1\;m{s^{ - 2}}$

  3. $4.2\;m{s^{ - 2}}$

  4. $0.3\;m{s^{ - 2}}$


Correct Option: A

A particle is projected vertically upward and is at a height h after $\displaystyle { t } _{ 1 }$ seconds and again after $\displaystyle { t } _{ 2 }$ seconds, then:

  1. $\displaystyle h={ gt } _{ 1 }{ t } _{ 2 }$

  2. $\displaystyle h=\frac { 1 }{ 2 } { gt } _{ 1 }{ t } _{ 2 }$

  3. $\displaystyle h=\frac { 2 }{ g } { t } _{ 1 }{ t } _{ 2 }$

  4. $\displaystyle h=\sqrt { { gt } _{ 1 }{ t } _{ 2 } } $


Correct Option: B
Explanation:

Let u be the velocity of the projection and O be the point of projection. Let P be the point in the path of the particle such that OP=h. Then,
$\displaystyle h=ut-\frac { 1 }{ 2 } { gt }^{ 2 }\Rightarrow { gt }^{ 2 }-2ut+2h=0$...(i)
Clearly, $\displaystyle { t } _{ 1 }{ t } _{ 2 }$, are two roots of this equation.
$\displaystyle \therefore \quad { t } _{ 1 }{ t } _{ 2 }=\frac { 2h }{ g } $
$\displaystyle \Rightarrow \quad h=\frac { 1 }{ 2 } g{ t } _{ 1 }{ t } _{ 2 }$

In case of an orbiting satellite, if the radius of orbit is decreased.

  1. Its KE decreases

  2. Its PE decreases

  3. Its ME decreases

  4. Its speed decreases


Correct Option: B,C
Explanation:

P.E of orbiting satellite at distance $r$ from centre of earth

$=\cfrac{-GMm}{r}\\K.E=\cfrac{GMm}{2R}$ and $M.E=\cfrac{-GMm}{2R}$

If $R$ decreased K.E increases.

P.E and M.E become more negative, thus decrease.

If for a given angle of projection, the horizontal range is doubled, the time of flight becomes

  1. $4 times$

  2. $2 times$

  3. $\sqrt 2 \;times$

  4. $\frac{1}{{\sqrt 2 }}\;times$


Correct Option: C
Explanation:
$r=\dfrac { { u }^{ 2 }\sin2\theta  }{ g } $
Hence $R=2r=\dfrac { { V }^{ 2 }2\sin2\theta  }{ g } $
${ u }^{ 2 }=\dfrac { { V }^{ 2 } }{ 2 } \Rightarrow V=\left[ { \left( 2 \right)  }^{ 1/2 } \right] 4$
$t=\dfrac { 2u\sin\theta  }{ g } $
$T=\dfrac { 2V\sin\theta  }{ g } $
    $=\dfrac { 2\times { 2 }^{ 1/2 }\times u\sin\theta  }{ g } $
    $=\left( { 2 }^{ 1/2 } \right) t$
    $={ \left( 2 \right)  }^{ 1/2 }$
    $=\sqrt { 2 } $ times

Two identical satellites are moving in the same circular orbit around the earth but in opposite senses of rotation, Assuming an inelastic collision to take place, so that the wreckage remains as one piece of tangled material  wreckage

  1. will be moving in a circular orbit of half the radius

  2. will be moving in a circular orbit on one fourth the radius

  3. will spin with no translatory motion

  4. falls directly down


Correct Option: C
Explanation:

The wreckage will spin with no translatory motion$.$

Hence,
option $(C)$ is correct answer.  

The full form of NASA is ?

  1. National Aerospace and Space Administration

  2. National Aeronautics and Satellite Administration

  3. National Aeronautics and Space Administration

  4. National Aeronautics and Space Academy


Correct Option: C
Explanation:

The National Aeronautics and Space Administration (NASA) is an independent agency of the US federal govt. responsible for the civilian space program and aeronautics and aerospace research.

State whether the given statement is True or False :

The space shuttle is moving van which carries astronauts and many things in space ?

  1. True

  2. False


Correct Option: A
Explanation:

The given statement is true. Space shuttle carries satellites to space for research work. Along with research, space shuttle is also used to carry astronauts on various heavenly bodies for research work.

The International space Station is currently under construction. Eventually, simulaced earth gravity may become a reality on the space station.What would the gravitational  field through the central axis be like under these conditions?

  1. zero

  2. $0.25 g$

  3. $0.5 g$

  4. $0.75 g$


Correct Option: A

When the temperature raised to $50^0C$, how did scientist adjust its temperature?

  1. The temperature was brought down by about $10^\circ C$ by rotating the spacecraft about 20 degrees and switching off some of the instruments

  2. The temperature was brought down by about$ 0^\circ C$ by removing the parts spacecraft.

  3. The temperature was brought down by about $30^\circ C$ by rotating the spacecraft about 100 degrees and by removing some of the instruments

  4. None of the above


Correct Option: A
Explanation:

Temperature was bought down by about $10°C$ by rotating the spacecraft $20$degrees and switching of some of the instruments.

Which of the following is an Air-to-Air Missile?

  1. Astra

  2. Aakash

  3. Prithvi

  4. None of these


Correct Option: A
Explanation:

Astra is an all weather beyond-visual-range air-to-air missile developed by the DRDO, India.