Correct trend regarding inductive effect isI)−NH2  <  −OH  < −Cl  <  −F.....  −I  effectII)  −CH3  <  −C2H5  <  −CHCH32  <  −CCH33  .......+I  effect

I) –I effect α Electronegativity but –I effect of all halo groups > – OH > – OR > – NH2II) As the bulkiness of alkyl group increases, +I effect increases.