Chapter: Gravitation – Question Paper
CBSE Class 11 Physics
Max Marks: 35
Time: 1 Hour
Section A – Multiple Choice Questions (MCQs) [1 × 5 = 5]
- The force of gravitation between two masses is F. If the mass of one object is doubled and the distance between them is halved, the new force will be:
(a) 2F
(b) 4F
(c) 8F
(d) 16F - The weight of an object at the center of the Earth is:
(a) Zero
(b) Infinite
(c) Same as on the surface
(d) None of these - The orbital velocity of a satellite increases when:
(a) The mass of the satellite increases
(b) The radius of the orbit decreases
(c) The gravitational constant increases
(d) The satellite moves away from the Earth - The escape velocity of a body from Earth depends on:
(a) The mass of the body
(b) The mass of the Earth and its radius
(c) Only on the mass of the Earth
(d) None of these - The time period of a satellite orbiting close to Earth is approximately:
(a) 24 hours
(b) 90 minutes
(c) 365 days
(d) 12 hours
Section B – Short Answer Questions (SA-I) [2 × 4 = 8]
- Explain Kepler’s first law of planetary motion with a diagram.
- Define gravitational potential energy and derive its expression for two masses separated by a distance r.
- Why does the Moon not fall towards the Earth even though it is under Earth’s gravitational influence?
- The mass of the Moon is 1/81 of Earth’s mass, and its radius is 1/4 of Earth’s radius. Find the acceleration due to gravity on the Moon.
Section C – Short Answer Questions (SA-II) [3 × 3 = 9]
- Derive an expression for the variation of acceleration due to gravity with altitude.
- A satellite revolves around the Earth at a height of 500 km. Calculate its orbital velocity. (Given: Radius of Earth = 6400 km, Gravitational constant G=6.67×10−11G = 6.67 \times 10^{-11}G=6.67×10−11 Nm²/kg², Mass of Earth M=5.972×1024M = 5.972 \times 10^{24}M=5.972×1024 kg)
- The gravitational force between two objects separated by 1 m is 10 N. What will be the force if the distance between them becomes 4 m?
Section D – Long Answer Questions (LA) [5 × 2 = 10]
- Derive an expression for escape velocity of a body from a planet’s surface and explain its significance.
- Explain the concept of geostationary and polar satellites. Discuss their uses and differences with suitable examples.
Instructions:
- Answer all questions in a stepwise manner.
- Show proper derivations and calculations where required.
- Use SI units in numerical problems.
This paper includes theory, derivations, and numerical problems to prepare students thoroughly for CBSE Class 11 Physics exams