1. | \(11.2\) km/s | 2. | \(22.4\) km/s |
3. | \(5.6\) km/s | 4. | \(44.8\) km/s |
The density of a newly discovered planet is twice that of the earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is \(R,\) the radius of the planet would be:
1. | \(4R\) | 2. | \(\frac{1}{4}R\) |
3. | \(\frac{1}{2}R\) | 4. | \(2R\) |
The universal gravitational constant is dimensionally represented as:
1. \(\left[ML^2T^{-1}\right]\)
2. \(\left[M^{-2}L^3T^{-2}\right]\)
3. \(\left[M^{-2}L^2T^{-1}\right]\)
4. \(\left[M^{-1}L^3T^{-2}\right]\)
Rohini satellite is at a height of \(500\) km and Insat-B is at a height of \(3600\) km from the surface of the earth. The relation between their orbital velocity (\(v_R,~v_i\)) is:
1. \(v_R>v_i\)
2. \(v_R<v_i\)
3. \(v_R=v_i\)
4. no specific relation
For moon, its mass is \(\frac{1}{81}\) of Earth's mass and its diameter is \(\frac{1}{3.7}\) of Earth's diameter. If acceleration due to gravity at Earth's surface is \(9.8\) m/, then at the moon, its value is:
1. | \(2.86\) m/s2 | 2. | \(1.65\) m/s2 |
3. | \(8.65\) m/s2 | 4. | \(5.16\) m/s2 |
1. | \(\frac{2}{9}\) m | 2. | \(18\) m |
3. | \(6\) m | 4. | \(\frac{2}{3}\) m |
Two spheres of masses \(m\) and \(M\) are situated in air and the gravitational force between them is \(F.\) If the space around the masses is filled with a liquid of specific density \(3,\) the gravitational force will become:
1. \(3F\)
2. \(F\)
3. \(F/3\)
4. \(F/9\)
1. | \(g' = 3g\) | 2. | \(g' = 9g\) |
3. | \(g' = \frac{g}{9}\) | 4. | \(g' = 27g\) |
A satellite is revolving in a circular orbit at a height \(h\) from the earth's surface (radius of earth \(R\); \(h<<R\)). The minimum increase in its orbital velocity required, so that the satellite could escape from the earth's gravitational field is close to: (Neglect the effect of the atmosphere.)
1. \(\sqrt{2gR}\)
2. \(\sqrt{gR}\)
3. \(\sqrt{\frac{gR}{2}}\)
4. \(\sqrt{gR}\left(\sqrt{2}-1\right)\)
The initial velocity \(v_i\) required to project a body vertically upwards from the surface of the earth to just reach a height of \(10R\), where \(R\) is the radius of the earth, described in terms of escape velocity \(v_e\) is:
1. \(\sqrt{\frac{10}{11}}v_e\)
2. \(\sqrt{\frac{11}{10}}v_e\)
3. \(\sqrt{\frac{20}{11}}v_e\)
4. \(\sqrt{\frac{11}{20}}v_e\)