Tag: space research and satellites

The objective lens produces a real, inverted image and the eyepiece acts as a simple magnifier and does not re-invert and produces a virtual image. So overall the image is inverted and virtual.

Here $F=180 \ cm$ and $f=30 \ cm$
$\therefore $ Magnifying power M
$=\dfrac {F}{f}=\dfrac {180}{3}=60$

Salyut 6 and Salyut 7 were the second generation of the Salyut programme which was the first space station programme undertaken by the Soviet Union. They both were built with two docking ports, one on either end of the station.

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.