Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

When a glass rod is rubbed with silk, both become charged due to:

  1. migration of protons

  2. exchange of electrons and protons

  3. migration of electrons

  4. migration of neutrons
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a glass rod is rubbed with silk cloth glass rod becomes positively charges while silk cloth becomes negatively charged. This is due to transfer or migration of electrons from glass rod to silk cloth.

Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

A glass rod when rubbed with silk cloth acquires a charge $1.6 \times 10^{-13}  C$. What is the charge on the silk cloth?

  1. $-1.6 \times 10^{-19} C$
  2. $1.6 \times 10^{-13} C$
  3. $-1.6 \times 10^{-13} C$
  4. $1.6 \times 10^{-19} C$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a glass rod is rubbed with silk, both gets electrified due to charging by friction. Given, glass rod acquires positive charge $=1.6\times 10^{-31}\, C$. So silk acquires equal and opposite charge as that on glass rod. Hence the answer is $-1.6\times 10^{-13}\, C$.

Multiple choice physics option d: astrophysics the big bang and the early development of the universe origin of universe evolution of the universe

The Hubble Deep Field is an image of the sky taken with a very along exposure, using the Hubble Space Telescope. Almost all of the $5000$ objects seen in that picture are?

  1. Starts that are in our own Galaxy.

  2. Dirt on the lens of the telescope.

  3. Galaxies

  4. Distant planets.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Hubble Deep Field image was a landmark observation that revealed thousands of distant galaxies in a tiny, seemingly empty patch of the sky, demonstrating the vast scale of the universe.

Multiple choice physics forces - vectors and moments centre of gravity turning effects of forces acceleration due to gravity

Can the centre of gravity be situated outside the material of the body ?

  1. Yes

  2. No

  3. Can't say

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

Yes, it can. For example, in case of a ring, it is situated at the centre of that circle. But the material is only along the circumference. Hence centre of gravity is situated outside the material of the body.

Multiple choice physics motion of system of particles and rigid bodies centre of gravity turning effects of forces forces - vectors and moments

What is the position of centre of gravity of a cylinder?

  1. At the center of base circle

  2. At the center of top circle

  3. Cannot be determined

  4. At the mid point on the axis of cylinder
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Centre of gravity means a point from which the weight of a body or system may be considered to act. In uniform gravity it is the same as the centre of mass. For regular shaped bodies it lies at the centre of the that particular body. Hence for a cylinder centre of gravity lies at the midpoint of the axis of the cylinder.

Multiple choice physics motion of system of particles and rigid bodies centre of gravity turning effects of forces forces - vectors and moments

In an artificial satellite, the use of a pendulum watch is discarded, because :

  1. The satellite is in a constant state of motion
  2. The effective value of $g$ becomes zero in the artificial satellite

  3. The periodic time of the pendulum watch is reduced

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pendulum watch relies on gravity to oscillate. Inside an orbiting satellite, objects are in a state of free fall, meaning the effective gravitational acceleration (g) is zero, causing the pendulum to stop oscillating.

Multiple choice physics motion of system of particles and rigid bodies centre of gravity turning effects of forces forces - vectors and moments

Given that there is a relationship between the orbital radius of a planet and its period of revolution and that the periods of revolution of Mercury, Earth, Jupiter and Neptune and nearly 0.24, 1, 11.8 and 165 years. It follows that the period of revolution of
1. Venus is less than 0.24 years
2. Mars is less than 12 years
3. Uranus is more than 165 years
4. Uranus is less than 165 years but more than 12 years.

  1. 1 and 3

  2. 4 only

  3. 3 o nly

  4. 2 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Kepler's third law states that the square of the orbital period is proportional to the cube of the semi-major axis (distance from the Sun). Therefore, planets further from the Sun have longer orbital periods. Mars (between Earth and Jupiter) must have a period between 1 and 11.8 years. Uranus (further than Neptune) would have a period longer than 165 years. The logic in option 2 and 4 fits the observed orbital distances.