Which of the following oxides is amphoteric in nature?

Select the correct statement.

In which of the following arrangements,the order is not correct according to the property indicated against it?

Let $P = \{\theta : \sin \theta - \cos \theta = \sqrt{2} \cos \theta\}$ and $Q = \{\theta : \sin \theta + \cos \theta = \sqrt{2} \sin \theta\}$ be two sets,then:

Identify the reaction for which $\Delta H \neq \Delta E$ :

$A$ transformer works on the principle of