One end of a string of length $L$ is tied to the ceiling of a lift accelerating upwards with an acceleration $2g$. The other end of the string is free. The linear mass density of the string varies linearly from $0$ to $\lambda$ from bottom to top.
  • AThe velocity of the wave in the string will be $0$.
  • BThe time taken by a pulse to reach from bottom to top will be $\sqrt {4L/3g} $ 
  • CThe time taken by a pulse to reach from bottom to top will be $\sqrt {8L/3g} $
  • Dboth $(B)$ and $(C)$
Diffcult
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