Practice free NEET NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
The period of moon’s rotation around th earth is nearly 29 days. If moon’s mass were 2 fold its present value and all other things remained unchanged the period of moons’s rotation would be nearly days
Time period does not depends upon the mass of satellite
If the velocity of planet is given by $ \upsilon = G^a M^b R^c $ then
$ \upsilon = \sqrt { GM \over R } = G^{1/2 } M^{1/2} R^{-1/2} $
What does not change in the field of central force
For central force toraqe is zero $ \therefore \tau = { dL \over dt } = 0 \Rightarrow L = constant $
Suppose the gravitational force varies inversely as the nth power of distance the time period of planet in circular orbit of radius R around the sun will be proportional to
$ m \omega ^2 R \alpha {1 \over R^n } \Rightarrow m \left( {4 \pi ^2 \over T^2} \right) $ $ R \alpha {1 \over R^n } \Rightarrow T^2 \alpha R^{n+1 } $ $ \therefore T \alpha R^ { n+1 \over 2 } $
If the radius of the earth were to shrink by 1% its mass remaing the same, the accelration due to gravity on the earth’s surface would
$ g = { GM \over R^2 } $ is mass remains constant then $ \rho \alpha {1 \over R^2 } $
A body of mass m is taken from earth surface to the height h equal to radius of earth, the increase in potential energy will be
$ \triangle U = { mgh \over 1 + {h / R} } = {1 \over 2 } mgR $
An artificial satellite moving in a circular orbit around earth has a total (kinetic + potential energy) Eo, its potential energy is
P.E. = 2. total energy = $2E_0$ Because we know $ U = -{GMM \over r } and Eo = - { GMM \over 2r } $
Two bodies of masses m1 and m2 are initially at rest at infinite distance apart. They are then allowed to move towards each other under mutual agravitational attraction Their relative velocity of apporach at sepration distance r between them is
let velocities of these masses at r distance from each other be v1 and v2 respectively By conservation of momentum $ m_1 V_1 - m_2 V_2 = 0 \Rightarrow m_1 V_1 = m_2 V_2 $....(i) By conservation of energy change in P.E. = change in K.E. $ {Gm_1 m_2 \over r } = { 1 \over 2 } m_1 V_1^2 + {1 \over 2 } m_2 V_2^2 $ $ \Rightarrow {m_1 V_1^2 \over m_1 } + { m_2 V_2^2 \over m_2 } = {2 Gm_1 m_2 \over r } $...(ii) on solving (i) and (ii) $ \upsilon_1 = \sqrt {2Gm_2^2 \over r (m_1 + m_2 } $ and $ \upsilon_2 = \sqrt {2Gm_1^2 \over r (m_1 + m_2 } $ $ Vapp = |V_1| + |V_2| = \sqrt { 2G (m_1 + m_2) \over r } $
A geostationary satellite orbits around the earth in a circular orbit of radus 3600 km the time period of a satellite orbiting a few hundred kilometers above the earth’s surface (Rearth = 6400 km) will approximately be = ………...h
$ {T_2 \over T_1 } = \left( {r_1 \over r_2} \right ) ^ {3/2} \Rightarrow T_2 = 24 \left( {6400 \over 3600} \right)^{3/2} = 2hours $
A branch of physics dealing with motion without considering its causes is known as ....
The branch of physics dealing with motion without considering its causes is known as kinematics. Kinematics focuses on describing how objects move, using concepts such as displacement, velocity, and acceleration, without analyzing the forces or energies involved in causing the motion.
Ready to ace NEET?
Free access · No credit card required
Yes. You can attempt every NEET question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.
No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.
The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.