A force $\mathrm{F}=2\hat{\mathrm{i}}+3\hat{\mathrm{j}}-\hat{\mathrm{k}}$  acts at a point (2,-3, 1). Then magnitude of torque about point (0,0,2) will be(all are in SI units)

$\overrightarrow{\mathrm{F}}=2\hat{\mathrm{i}}+3\hat{\mathrm{j}}-\hat{\mathrm{k}}$ at point  (2,–3,1) torque about point  (0, 0, 2)  
$\begin{array}{l}\overrightarrow{\mathrm{r}}=(2\widehat{\mathrm{i}}-3\widehat{\mathrm{j}}+\widehat{\mathrm{k}})-2\widehat{\mathrm{k}}\\ \overrightarrow{\mathrm{\tau }}=\overrightarrow{\mathrm{r}}\times \overrightarrow{\mathrm{F}}=(2\widehat{\mathrm{i}}-3\widehat{\mathrm{j}}-\widehat{\mathrm{k}})\times (2\widehat{\mathrm{i}}+3\widehat{\mathrm{j}}-\widehat{\mathrm{k}})\\ \overrightarrow{\mathrm{\tau }}=(6\widehat{\mathrm{i}}+12\widehat{\mathrm{k}})\mathrm{◻}\left|\overrightarrow{\mathrm{\tau }}\right|=\left(6\sqrt{5}\right)\end{array}$