What is the current through an ideal $PN-$ junction diode shown in the figure below? (in $mA$)

Data Entry - Physics

Identify $A$ and $B$ in the following reaction:
$CH_3-CH_3 \xleftarrow{B} CH_3COOH \xrightarrow{A} CH_3CH_2OH$

$A$

$B$

An observer is standing $500 ~m$ away from a vertical hill. Starting between the observer and the hill,a police van sounding a siren of frequency $1000 ~Hz$ moves towards the hill with a uniform speed. If the frequency of the sound heard directly from the siren is $970 ~Hz$,the frequency of the sound heard after reflection from the hill (in $Hz$) is about,(velocity of sound $= 330 ~m/s$):

The force $\vec{F} = 7\widehat{i} + 3\widehat{j} - 5\widehat{k}$ acts on a particle whose position vector is $\vec{r} = \widehat{i} - \widehat{j} + \widehat{k}$. What is the torque of the given force about the origin?