Alcohols of low molecular weight are

The major product obtained by the dehydration of the given alcohol is:

Which of the following alcohols is most easily dehydrated with concentrated ${H_2SO_4}$?

Which of the following statements is correct regarding the ease of dehydration of alcohols?

The following transformation involves a carbocation rearrangement. The carbocation is generated by protonation of the hydroxyl group,followed by the loss of water. Which bond has to migrate in the carbocation to yield the product indicated (after the deprotonation)?

$C_2H_5Br$ $\xrightarrow{aq.\,NaOH} X$ $\xrightarrow[H_2SO_4]{Na_2Cr_2O_7} Y$
$[Y]$ is