physics : class11 Aphelion Distance : Second Law of Kepler : Gravitation MCQ Questions and Answers
Practice important
Aphelion Distance
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. What is the aphelion distance of a planet?
A.
Its shortest distance from the Sun
B.
Its greatest distance from the Sun
C.
Its average orbital speed
D.
The time taken to complete one orbit
Correct Answer:
Its greatest distance from the Sun
Explanation:
Aphelion distance is the maximum distance between a planet and the Sun during its elliptical orbit.
2. At which point in its orbit is a planet at aphelion?
A.
When it is closest to the Sun
B.
When it is farthest from the Sun
C.
When its speed is maximum
D.
When its orbit becomes circular
Correct Answer:
When it is farthest from the Sun
Explanation:
Aphelion is the point on an elliptical orbit where the planet has its greatest distance from the Sun.
3. For an elliptical orbit with semi-major axis a and eccentricity e, the aphelion distance is:
A.
a(1 - e)
B.
a/e
C.
a(1 + e)
D.
ae
Correct Answer:
a(1 + e)
Explanation:
The aphelion distance is given by r_a = a(1 + e), where a is the semi-major axis and e is the eccentricity.
4. If the semi-major axis of an orbit is 10 units and its eccentricity is 0.2, what is its aphelion distance?
A.
8 units
B.
10 units
C.
12 units
D.
20 units
Correct Answer:
12 units
Explanation:
Using r_a = a(1 + e), the aphelion distance is 10(1 + 0.2) = 12 units.
5. If the eccentricity of an elliptical orbit increases while its semi-major axis remains constant, what happens to the aphelion distance?
A.
It decreases
B.
It increases
C.
It becomes zero
D.
It remains unchanged in every case
Correct Answer:
It increases
Explanation:
Since r_a = a(1 + e), increasing eccentricity increases the aphelion distance when the semi-major axis is fixed.
6. At aphelion, the orbital speed of a planet is generally:
A.
Greater than at perihelion
B.
Less than at perihelion
C.
Always zero
D.
Equal to the speed of light
Correct Answer:
Less than at perihelion
Explanation:
According to Kepler's second law, a planet moves more slowly when it is farther from the Sun, so its speed is lower at aphelion than at perihelion.
7. A planet takes equal time to sweep equal areas near aphelion and perihelion. Compared with perihelion, the distance traveled near aphelion is:
A.
Greater because the planet is farther away
B.
Smaller because the planet moves more slowly
C.
Always zero
D.
Exactly twice as large
Correct Answer:
Smaller because the planet moves more slowly
Explanation:
Kepler's second law requires equal areas in equal times. At aphelion the planet is farther from the Sun and moves more slowly, so the distance traveled in the same time is smaller.
8. If an orbit has semi-major axis 8 units and eccentricity 0.5, what is the aphelion distance?
A.
4 units
B.
8 units
C.
12 units
D.
16 units
Correct Answer:
12 units
Explanation:
The aphelion distance is r_a = a(1 + e) = 8(1 + 0.5) = 12 units.
9. For a circular orbit, where the eccentricity is zero, the aphelion distance is equal to:
A.
Zero
B.
Half the radius
C.
The orbital radius
D.
Twice the orbital radius
Correct Answer:
The orbital radius
Explanation:
For e = 0, the orbit is circular and r_a = a(1 + 0) = a. The aphelion distance is therefore the same as the constant orbital radius.
10. If a planet's aphelion distance is 15 units and its semi-major axis is 10 units, what is its eccentricity?
A.
0.25
B.
0.5
C.
1.5
D.
5
Correct Answer:
0.5
Explanation:
Using r_a = a(1 + e), 15 = 10(1 + e), so 1 + e = 1.5 and e = 0.5.
Short Questions and Answers
Practice short questions and answers related to
Aphelion Distance
.
Short questions are currently unavailable for this page.