Tag: space travel

The space station launched are broadly classified into two types: 

1. Monolithic : earlier space station, Salyut and Skylab in which were constructed and launched in one piece, and then manned by a crew later. 
2. Modular: Mir and ISS, a core unit was launched, and additional modules, generally with a specific role, were later added to that.

Salyut and Skylab were built monolithic meaning that they were constructed and launched in one piece, and then manned by a crew later. 

Space stations are made to conduct experiments that needs to be done out in space. It is used to study the effects of long-duration space flight on human body. These provides a platform for greater number and length of scientific studies than it is available on other space vehicles and other military and civilian purposes.

• The visible light spectrum is the section of the electromagnetic radiation spectrum that is visible to the human eye. 
• It ranges in wavelength from approximately 400 nanometers ($4 \times  10 ^{-7}$ m, which is violet) to 700 nm ($7 \times 10^{-7}$ m, which is red).
  
• Hence wavelengths are infinite
• Option D is the right answer

Cosmic rays, γ-rays, and X-rays are part of electromagnetic spectrum, while β-rays are emitted by radioactive elements. Hence β-rays is not electromagnetic waves.

Astronomical telescopes uses convex lenses which form real and inverted image of object at infinite distance.

Telescopes objective lenses have large apertures so that more number of light rays coming from object should enter and have greater resolution.

To get a magnified image of an object at infinity the image formed by objective lens will beat focus and if we want maximum magnification then the image formed by objective should be at focus of the eye piece.

simple microscope is placed between the optic center and the focus and the image is erect, virtual and magnified.