The basic strength of $1,8-$bis(dimethylamino)naphthalene is $10^{10}$ times more than $1-$dimethylaminonaphthalene. The reason for this high basic strength is:

What is the electromeric effect?

Which of the following is an incorrect representation of the electromeric effect?

Rank the following compounds in order of increasing acidity (weakest acid first).

Match List-$I$ with List-$II$:
| List-$I$ (Mechanism steps) | List-$II$ (Effect) |
| :--- | :--- |
| $(A)$ Aniline resonance structure | $(I)$ $-E$ effect |
| $(B)$ Electrophilic addition of $H^+$ to alkene | $(II)$ $-R$ effect |
| $(C)$ Nucleophilic addition of $CN^-$ to alkene | $(III)$ $+E$ effect |
| $(D)$ Nitrobenzene resonance structure | $(IV)$ $+R$ effect |
Choose the correct answer from the options given below:

The functional group that shows negative resonance effect ($-R$ effect) is: