Let $\quad \overrightarrow{O P}=\frac{\alpha-1}{\alpha} \hat{i}+\hat{j}+\hat{k}, \overrightarrow{O Q}=\hat{i}+\frac{\beta-1}{\beta} \hat{j}+\hat{k} \quad$ and $\quad \overrightarrow{O R}=\hat{i}+\hat{j}+\frac{1}{2} \hat{k} \quad$ be three vectors, where $\alpha, \beta \in R-\{0\}$ and $O$ denotes the origin. If $(\overrightarrow{O P} \times \overrightarrow{O Q}) \cdot \overrightarrow{O R}=0$ and the point $(\alpha, \beta, 2)$ lies on the plane $3 x+3 y-z+l=0$, then the value of $/$ is $\_\_\_\_$