[" 29.A proton and an a-particle enter a uniform "],[" magnetic field perpendicular to y-axis with the same "],[" speed.If proton takes "25 mu" sec to make "5" revolutions,"],[" then time period for the "alpha" -particle would be "],[[" (a) "5 mu" sec "," (b) "10 mu" sec "],[" (c) "25 mu" sec "," (d) "50 mu" sec [VMMC 2003] "]]