Satellites

Q.

Two satellites of masses 3m and m orbit the earth in circular orbits of radii r and 3r respectively. The ratio of their orbital speeds is

1. $1$

2. $\frac{1}{2\sqrt{3}}$

3. $\frac{1}{3}$

4. $\sqrt{3}$

Q.

What is the meaning of "cometh the hour, cometh the man"?

Q. Two particles of mass $5\text{kg}$ and $10\text{kg}$ respectively are attached to the two ends of a rigid rod of length $1\text{m}$ with negligible mass. The centre of mass of the system from the $5\text{kg}$ particle is nearly at a distance of :

1. $67\text{cm}$
2. $80\text{cm}$
3. $33\text{cm}$
4. $50\text{cm}$

Q. A solid sphere of mass $m$ and radius $R$ is rotating about its diameter. A solid cylinder of the same mass and same radius is also rotating about its geometrical axis with an angular speed twice that of the sphere. The ratio of their kinetic energy of rotation $\left(\frac{E_{sphere}}{E_{\mathrm{cylinder}}}\right)$ will be

1. 1 : 5
2. 1 : 4
3. 3 : 1
4. 2 : 3

Q.

What is the difference between perihelion and aphelion?

Q.

What is the difference Between a Simple Pendulum and a Compound Pendulum?

Q.

The moon is observed from two diametrically opposite points A and B on earth.The angle Q substended at the moon by the two directions of observation is 1°54'.Given the diameter of the to be about 1.276×10^7m, compute the distance of the moon from the earth.

Q. For a satellite very close to surface of earth, we get time period of satellite equal to

1. 85 minutes
2. 60 minutes
3. 40 minutes
4. 24 minutes

Q.

A body weighs $49N$ on a spring balance at the north pole. What will be its weight recorded on the same weighing machine, if it is shifted to the equator?

[Use $g=GM/R^2=9.8m{s}^{-2}$ and radius of earth, $R=6400km$]

1. $49N$

2. $49.83N$

3. $49.17N$

4. $48.83N$

Q. Time period of a satellite revolving above Earth’s surface at a height equal to R, where R the radius of Earth, is

1. $4\pi \sqrt{\frac{R}{g}}$
2. $4\pi \sqrt{\frac{2R}{g}}$
3. $8\pi \sqrt{\frac{R}{g}}$
4. $8\pi \sqrt{\frac{2R}{g}}$

Q.

A satellite does not need any fuel to circle around the earth why?

Q. Mass of moon is 1% mass of earth . What will be the ratio of gravitational pull of earth on moon to moon on earth

Q. The radii of circular orbits of two satellites $A$ and $B$ of the earth are $4R$ and $R$ respectively. If the speed of satellite $A$ is $3v$, then the speed of satellite $B$ will be

1. $3v/2$
2. $3v/4$
3. $6v$
4. $12v$

Q. A satellite moves around the earth in a circular orbit of radius $r$ with speed $v$. If the mass of the satellite is $M$, its total energy is

1. ${\text{Mv}}^2$
2. $\frac{1}{2}{\text{Mv}}^2$
3. $-\frac{1}{2}{\text{Mv}}^2$
4. $-\frac{3}{2}{\text{Mv}}^2$

Q.

Two satellites are moving around the earth in circular orbits at height R and 3R respectively, R being the radius of the earth, the ratio of their kinetic energies is

1. 2

2. 4

3. 8

4. 16

Q. Force of gravitation between two masses is found to be $F$ in vacuum. If both the masses are dipped in water at same distance then, new force will be

1. greater than $F$.
2. less than $F$.
3. equal to $F$.
4. cannot say

Q. The mean radius of the earth is R, its angular speed on its own axis is $\omega$ and the acceleration due to gravity at earth's surface is g. The cube of the radius of the orbit of a geostationary satellite will be

1. 
2. 
3. 
4. 

Q.

Potential energy of a satellite having mass ‘m’ and rotating at a height of $6.4\times {10}^6$ from the earth centre is

1. 

2. 

3. 

4. 

Q. A satellite of mass $1000kg$ is rotating around the earth in a circular orbit of radius $3R$. What extra energy should be given to this satellite, if it is to be lifted into an orbit of radius $4R$?

1. $4.8\times {10}^{9}J$
2. $2.7\times {10}^{9}J$
3. $3.9\times {10}^{9}J$
4. $6.4\times {10}^{9}J$

Q.

A body of mass m kg. starts falling from a point 2R above the Earths surface. Its kinetic energy when it has fallen to a point R above the Earths surface [R-Radius of Earth, M-Mass of Earth, G-Gravitational Constant]

1. 

2. 

3. 

4. 

Q. Two identical satellites are at 7R and R away from earth surface, the wrong statement is (R = Radius of earth)

1. Ratio of total energy will be 4
2. Ratio of potential energies will be 4
3. Ratio of total energy will be 4 but ratio of potential and kinetic energies will be 2
4. Ratio of kinetic energies will be 4

Q. A particle moving with kinetic energy $E$, has de-Broglie wavelength $\lambda$. If energy $\Delta E$ is added to it, the wavelength become $\lambda /2$. The value of $\Delta E$ is,

1. $2E$
2. $E$
3. $3E$
4. $4E$

Q. Why is difference between geostationary satellits and polar satellite

Q.

A body is projected vertically upward direction from the surface of earth. If upward direction is taken as positive, then acceleration of body during its upward and downward journey are respectively

Ans:- negative, negative

Please explain why is this so?????

Q. The de-Broglie wavelength of a particle having kinetic energy E is $\lambda$. How much extra energy must be given to this particle so that the de-Broglie wavelength reduces to $75\%$ of the initial value ?

1. $\frac{16}{9}E$
2. $E$
3. $\frac{7}{9}E$
4. $\frac{1}{9}E$

Q.

_______ is the closest celestial body to our earth.

Q.

The distance of a geostationary satellite from the centre of the earth(R=6400km) is nearest to

Q.

A satellite is moving around the with speed v in a circular orbit of radius r. If the orbit radius is decreased by $1\%$, its speed will

1. 

2. 

3. 

4. 

Q.

Define Uniform circular motion?

Q. An earth satellite $S$ has an orbit radius which is $4$ times that of a communication satellite $C$. The period of revolution of $S$ is

1. 8 days
2. 4 days
3. 16 days
4. 32 days