The delocalization of $\sigma$ electrons of $C-H$ bond of an alkyl group with the $\pi$ electrons of benzene is observed in

Rank the hydrogen atoms $(H_a, H_b, H_c)$ in the following molecule according to their acidic strengths.

Which of the following represents the hyperconjugation effect?

Which of the following statements are not correct?
$a$. The energy of resonance hybrid structure is higher than that of the possible canonical structures of the molecule.
$b$. When inductive effect and electromeric effect operate in opposite directions,electromeric effect predominates.
$c$. When the $\pi$ electrons of the multiple bond are transferred to that atom to which the attacking reagent does not get attached,it is known as $+E$ effect.
$d$. The resonance structures with separation of opposite charges are more stable.

Which of the following can show $+M$ or $+R$ effect?

Which among the following pairs of electronic effect and its example is $NOT$ correct?