In: Physics
Answer __
(1) According to the Einstein`s theory of relativity the velocity of light is the maximum attainable velocity and not depend on the frame so the velocity of the light will remain c .
option (a) is correct .
(2 ) as we know that the time dilation phenomenon according to which moving clock ticks slowly . so the event will be longer for the observer in motion .
option (a) is correct .
(3) now this is from Photo - electric effect according to which when the light of frequency greater than the threshold frequency falls on the metal surface electron will ejected from the surface of the metal . and according to the experimental results when we increase the intencity of the light the number of the electron ejected from the metal increases . and on increasing the frequency the kinetic energy of the photo electron will increases .
so the option (c) is correct .
(4) the wok function of the metal = the minimum energy required to eject the electron from the surface = hv0 so
the kinetic energy of the ejected electron is
so the greater the work function smaller the kinetic energy as well as the velocity of the ejected electron.
option (b) is correct .