Question

What does the NuSTAR, a space-based X-ray telescope, study?
A. Stars
B. Comets
C. Asteroids
D. Black holes

Answer 1

In order to solve this question we need to understand X-ray and how it is produced. X-ray are high energy electromagnetic beams having high penetration power.These rays have wavelengths ranging from $10\,picometers$ to $10\,nanometers$ ,X rays are shorter than Ultraviolet rays.

Complete answer:
These x-ray are produced by accelerating electrons through potential difference and target them to a material tungsten which produces X-ray radiation. These rays are very helpful in space as in space there are many sources which are at very high temperature and hence they release X-rays which can be studied on earth.

NuSTAR telescope or Nuclear Spectroscopic Telescope Array are a series of X-ray telescopes orbiting in space to study Black holes as black holes are considered to be one of the most energetic and have high gravitational pull so that even light can’t escape from it.

NuSTAR was launched in June $2012$ revolves around earth and has primary objectives like conducting a census for black holes on all scales using wide-field surveys of extragalactic fields and the Galactic center.

Hence, the correct answer is option D.

Note: It should be remembered that X-rays are very useful in nature as they can be used to study nanomaterials through crystal diffraction techniques that were initially developed by Bragg. Bragg gave a famous equation of Bragg law of diffraction in which X-rays fall on crystal structure which get reflected and later it was collected to study lattice patterns.