1) The magnetic field in a travelling electromagnetic wave has a peak value of 20 nT. The peak value of electric field strength is A) 3 V/m B) 6 V/m C) 9 V/m D) 12 V/m Answer: Option BExplanation:From question, B0 = 20 nT = 20×10-9 T $\vec{E_{0}} = \vec{B_{0}}\times\vec{C}$ $|\vec{E_{0}}| = |\vec{B_{0}}|.|\vec{C}|$ = 20 x 10-9 x 3 x 108 = 6 V/m (velocity of light in vacuum C = 3 x 108 ms-1)
