Q. With reference to standard model of particle physics, consider the following statements:
1.The standard model is thought to be incomplete because it omits gravity.
2.The model does not include clear description of dark matter particles.
Which of the statements given above is/are correct?

[A] 1 only

[B] 2 only

[C] Both 1 and 2

[D] Neither 1 nor 2

Answer: C
Notes:

Both the statements are correct

The Standard Model of Elementary Particles is a theoretical construct in physics that describes particles of matter and their interaction.

It is a description that views the elementary particles of the world as being connected by mathematical symmetries, just as an object and its mirror image are connected by a bilateral (left-right) symmetry.

However, the standard model believed to be incomplete because,

  • The standard model is thought to be incomplete because it gives a unified picture of only three of the four fundamental forces of nature — electromagnetic, weak nuclear, strong nuclear and gravitational interactions — it totally omits gravity.
  • The model does not include a description of dark matter particles. So far these have been detected only through their gravitational pull on surrounding matter.

Source: The Hindu