Aconverging lens (l) of focal length f =40 cm, gives for an object ab placed at a distance d from (l) an image a’b’ we give successively to d the following value 10cm indicate with justification the value of a’b’

Stars x and y are both bluish main sequence stars. star x has a higher absolute brightness than star y. how do the two stars compare? explain

What is the scientific definition of energy that relates to work

An initially unpolarized light if intensity 500 w/m^2 passes through four polarizers. the transmission axis between adjacent polarizers is 45∘. what percentage of the initial intensity is transmitted by the system?