Tag: physics

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Questions Related to physics

Multiple choice physics our solar system planets of the solar system solar system and sun introduction to solar system

Why does Venus show phases like the moon?

  1. It rotates from East to West

  2. It is covered by clouds

  3. Its atmosphere is dense

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Just like moon, Venus too rotates from East to West. Thus, only that part of Venus is visible to us which reflects the light from the Sun towards us. Hence, the Venus appears to show phases because the Earth and Venus rotate in opposite direction.

Multiple choice physics our solar system planets of the solar system solar system and sun introduction to solar system

Degenerate electron pressure will not be sufficient to prevent the core collapse of white dwarf if its mass becomes n times of our solar mass. Value of n is:

  1. 0.5

  2. 0.8

  3. 1

  4. 1.4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the definition of Chandrasekhar's Limit . 
Degenerate electron pressure will not be sufficient to prevent core collapse of white dwarf if its mass becomes 1.4 times or more of our solar mass.

Multiple choice physics our solar system planets of the solar system solar system and sun introduction to solar system

The planets keep changing their position with respect to:

  1. Galaxy

  2. Stars

  3. Venus

  4. Moon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Planets are solid heavenly bodies which revolve around the Sun in closed elliptical paths. A planet is made of rock and metal and produces no light of its own. A planet shines because it reflects the light of the Sun. Since, the planets are much nearer to the stars, they appear to be big and do not twinkle at night. The planets move around the Sun from West to East, so the relative positions of the planets keep changing day by day. They are very small compared to the sun and other stars. 
Hence, the star appears to remain in a fixed position with respect to each other whereas the distance between the planets keep changing constantly.

Multiple choice physics our solar system planets of the solar system solar system and sun introduction to solar system

The planets do not emit light of their own. This statement is:

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Planets are solid heavenly bodies which revolve around the Sun in a closed elliptical paths. A planet is made of rock and metal and produces no light of its own. A planet shines because it reflects the light of the Sun. Since, the planets are much nearer to the stars, they appear to be big and do not twinkle at night.
Hence, the statement is true.

Multiple choice physics our solar system planets of the solar system solar system and sun introduction to solar system

The earth revolves about the sun in an elliptical orbit with mean radius $9.3 \times 10^7\ m$ in a period of $1$ year. Assuming that there are no outside influences, then

  1. The earth's kinetic energy remains constant.

  2. The earth's angular momentum remains constant.

  3. The earth's potential energy remains constant.

  4. All the statements above are correct.
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice physics our solar system planets of the solar system solar system and sun introduction to solar system

The mass of a planet Jupiter is $1.9 \times 10^{27} kg$ and that of the Sun is $1.99 \times 10^{30} kg$. The mean distance of the Sun from Jupiter is $7.8 \times 10^{11} m$. The gravitational force, which the Sun exerts on Jupiter is.

  1. $4.1 \times 10^{23} N$
  2. $4.1 \times 10^{34} N$
  3. $2.2 \times 10^{23} N$
  4. $2.2 \times 10^{34} N$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using Newton's Law of Universal Gravitation, F = G * (m1 * m2) / r^2. Plugging in G = 6.67e-11, m1 = 1.9e27, m2 = 1.99e30, and r = 7.8e11, the calculation yields approximately 4.1e23 N.