# Let us assume that our galaxy consists of 2.5 × ${10}^{11}$ stars each of one solar mass. How long will a star at a distance of 50,000 ly from the galactic centre take to complete one revolution? (The diameter of the milky way is ${10}^{5}$ ly.) 1. 3.55 × 108 years 2. 4.55 × 108 years 3. 3.55 × 107 years 4. 4.55 × 107 years

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

The escape speed of a body from the earth depends on:

1. the mass of the body.
2. the location from where it is projected.
3. the direction of projection.
4. the height of the location from where the body is launched.

Subtopic:  Escape velocity |
71%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A comet orbits the sun in a highly elliptical orbit. The comet has a constant:
1. linear speed
2. angular speed
3. angular momentum
4. kinetic energy

Subtopic:  Orbital velocity |
86%
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

Which of the following symptoms is not likely to afflict an astronaut in space?

1. swollen feet
2. swollen face
4. orientational problem

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

The gravitational intensity at the centre of a hemispherical shell of uniform mass density has the direction indicated by the arrow:

1. a, d
2. b, d
3.
c, e
4. d, e

Subtopic:  Gravitational Field |
67%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A rocket is fired from the earth towards the sun. At what distance from the earth’s centre is the gravitational force on the rocket zero?

Given, the mass of the sun = $2×{10}^{30}$ kg, the mass of the earth =  $6×{10}^{24}$kg, and orbital radius = $1.5×{10}^{11}$ m. Neglect the effect of other planets etc.
1. 2.59 × 108 m
2. 3.10 × 108 m
3. 4.07 × 108 m
4. 2.23 × 108 m

Subtopic:  Gravitational Field |
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

If the mean orbital radius of the earth around the sun is . Then the mass of the sun is approximately:
1. 3 × 1034 kg
2. 2 × 1030 kg
3. 1.5 × 1028 kg
4. 1.0 × 1035 kg

Subtopic:  Newton's Law of Gravitation |
61%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A Saturn year is 29.5 times the earth year. How far is Saturn from the sun if the earth is  away from the sun?
1. 2.01 × 1012 m
2. 3.86 × 1012 m
3. 1.43 × 1012 m
4. 4.19 × 1012 m

Subtopic:  Kepler's Laws |
55%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A body weights $$63$$ N on the surface of the earth. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth?
1. $$98~\text N$$
2. $$35~\text N$$
3. $$63~\text N$$
4. $$28~\text N$$

Subtopic:  Acceleration due to Gravity |
74%
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

Assuming the earth to be a sphere of uniform mass density, how much would a body weigh halfway down to the centre of the earth if it weighed $$250$$ N on the surface?

 1 $$250$$ N 2 $$125$$ N 3 $$175$$ N 4 $$145$$ N
Subtopic:  Acceleration due to Gravity |
83%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints