In order to make the effective acceleration due to gravity equal to zero at the equator, the angular velocity of rotation of the earth about its axis should be: (\(g= 10~\text{ms}^{-2}\) and the radius of the earth is \(6400\) kms)
1. \(0~\text{rad/s}\)
2. \(\frac{1}{800}~\text{rad/s}\)
3. \(\frac{1}{80}~\text{rad/s}\)
4. \(\frac{1}{8}~\text{rad/s}\)

Subtopic:  Acceleration due to Gravity |
 71%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A body of mass \(m\) is taken from the earth's surface to the height \(h\) equal to the radius of the earth, the increase in potential energy will be:
1. \(mgR\)
2. \(\frac{1}{2}~mgR\)
3. \(2 ~mgR\)
4. \(\frac{1}{4}~mgR\)

Subtopic:  Gravitational Potential Energy |
 81%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Time period of a satellite revolving above Earth’s surface at a height equal to \(R\) (the radius of Earth) will be:
(\(g\) is the acceleration due to gravity at Earth’s surface)
1. \(2 \pi \sqrt{\frac{2 R}{g}}\)
2. \(4 \sqrt{2} \pi \sqrt{\frac{R}{g}}\)
3. \(2 \pi \sqrt{\frac{R}{g}}\)
4. \(8 \pi \sqrt{\frac{R}{g}}\)

Subtopic:  Satellite |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

An artificial satellite moving in a circular orbit around the earth has a total (kinetic + potential) energy E0 . Its potential energy is:

(1) -E0                       

(2) 1.5 E0

(3) 2E0                         

(4) E0

Subtopic:  Gravitational Potential Energy |
 78%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Given the radius of Earth ‘R’ and length of a day ‘T’, the height of a geostationary satellite is:

[G–Gravitational Constant, M–Mass of Earth] 

(a) 4π2GMT213                      (b) 4πGMR213-R

(c) GMT24π213-R                   (d) GMT24π213+R

Subtopic:  Kepler's Laws |
 67%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A rocket of mass \(M\) is launched vertically from the surface of the earth with an initial speed \(v\). Assuming the radius of the earth to be \(R\) and negligible air resistance, the maximum height attained by the rocket above the surface of the earth is:
1. \(\frac{R}{\left(\frac{gR}{2v^2}-1\right)}\)
2. \(R\left({\frac{gR}{2v^2}-1}\right)\)
3. \(\frac{R}{\left(\frac{2gR}{v^2}-1\right)}\)
4. \(R{\left(\frac{2gR}{v^2}-1\right)}\)

Subtopic:  Gravitational Potential Energy |
 65%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

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 gravitational attraction. Their relative velocity of approach at a separation distance r between them is

(1) 2G(m1-m2)r1/2                         

(2) 2Gr(m1+m2)1/2

(3) r2G(m1m2)1/2                             

(4) 2Grm1m21/2

Subtopic:  Gravitational Potential Energy |
 66%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The rotation period of an earth satellite close to the surface of the earth is 83 minutes. The time period of another earth satellite in an orbit at a distance of three earth radii from its surface will be

(1) 83 minutes                                   

(2) 83×8 minutes

(3) 664 minutes                                 

(4) 249 minutes

Subtopic:  Kepler's Laws | Satellite |
 63%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A satellite of mass m is circulating around the earth with constant angular velocity. If the radius of the orbit is R0 and mass of the earth M, the angular momentum about the centre of the earth is:

(1)mGMR0                                         

(2)MGmR0

(3)mGMR0                                           

(4)MGMR0

Subtopic:  Orbital velocity |
 65%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

If the distance between the earth and the sun becomes half its present value, the number of days in a year would have been
(1) 64.5                                     

(2) 129

(3) 182.5                                   

(4) 730

Subtopic:  Kepler's Laws |
 68%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch