Question

If electric and magnetic field strengths vary sinusoidally in time at frequency f = 2.83 GHz, being zero at t = 0, then E = E, sin(2neft) and B = B, sin(2nft). (a) After t = 0, when are the field strengths first zero? (Give your answer in seconds.) (b) After t = 0, when do they first reach their most negative value? (Give your answer in seconds.) (c) How much time (in s) is needed for them to complete one cycle?

Answer 1

solution : given frequency f: 2.83 Hz E = E, Sin (29f t) and B = Bosin (arft) (a) As we know that sino = 0 when ozor nr.......... nr where n=0, 1, 2..... so sin (2011) = 0 when 2014-0,, 237 ..... After t=0 nift=r t = r = It= 0.1775] OR/T=0.185] 0:7775 217 37*2.83 - sin 120ft) = -1 when 2947 to with = 0,575 = 0-245 so/t= 095]/730-2655] we know that time period of one cycle for Sin carft) is 20 i.e. eft=an = t = 1 = 2 It = 0.3557 16) --0.355 2.33 f