The e/m ratio of cathode ray particles is constant. The e/m ratio of an electron was found to be 1.76 x 108 coulombs/gram. The e/m ratio is also called specific charge. It is determined by J.J. Thomson. In 1908, R.A. Mullikan determined the charge of an electron to be 1.6 × 10-19 C. m =1.76x10°C/g The Specific Charge for cathode rays
a)constant
b)variable
c)depend upon the material of the cothode
d)depend on the nature of gas in discharge tube​