6.A photo cell with a constant potential difference of V volts applied across its ends is illuminated by a point source from a distance of 25 cm. If the source is moved to a distance of 1 m, then electrons emitted from the photo cell will be

7.Rest mass energy of an electron is 0.54 MeV. If velocity of the electron is 0.8 C, then K.E. of the electron is

8.A proton is accelerated through one volt. The increase in it K.E. is approximately

9.In Einstein s photoelectric equation E = hv - W, where E stands for

10.If wavelength of an electron and a photon is same, then they will have same