Reflection of wave in string from fixed end, reflected wave phase change by π. And reflected wave from free (rarer) end No phase change. ∵ω=kV ω=k√
T
µ
given y=y0cos(ωt−kx)cm
√T
µ
= const. For medium PQ(S2) kS2=kPQ=2k For medium S3 kS3=4k Option (A) reflection from P, phase change by π, No change in ' k '. Hence correct option. In option (B) ks2=2k but in option given ks=k Hence wrong. In option (C) direction of reflected wave in negative direction. Hence wrong. Option (D) no phase change in transmitted wave and given ks3=4k
