If a bimetallic strip is heated,it will

Which one of the following elements,when present as an impurity in silicon,makes it a $p$-type semiconductor?

In which of the following reactions is an aromatic aldehyde treated with an acid anhydride in the presence of the corresponding salt of the acid to give an unsaturated aromatic acid?

If $\overrightarrow{a}=\hat{i}+\hat{j}+\hat{k}$,$\overrightarrow{b}=\hat{i}+\hat{j}$,$\overrightarrow{c}=\hat{i}$ and $(\overrightarrow{a} \times \overrightarrow{b}) \times \overrightarrow{c}=\lambda \overrightarrow{a}+\mu \overrightarrow{b}$,then $\lambda+\mu$ is equal to:

The period of $\left(\tan \theta - \frac{1}{3} \tan^3 \theta\right) \left(\frac{1}{3} - \tan^2 \theta\right)^{-1}$,where $\tan^2 \theta \neq \frac{1}{3}$,is

Which of the following pair of ores cannot be converted into corresponding metals by pyrometallurgy?