Question

A sample of HCl is placed in an electric field of $2.5\times {10}^{4}N{C}^{-1}$. The dipole moment of HCl is $3.4\times {10}^{-30}Cm.$ Find the maximum torque that can act on a molecule.

• A. $7.6\times {10}^{-26}Nm$
• B. $4.3\times {10}^{-26}Nm$
• C. $6.5\times {10}^{-26}Nm$
• D. $8.5\times {10}^{-26}Nm$

Answer 1

The correct option is D $8.5\times {10}^{-26}Nm$

Torque ,$\overrightarrow{\tau }=\overrightarrow{p}\times \overrightarrow{E}=pE\sin \theta$
$\therefore {\tau }_{max}=pE$
$=3.4\times {10}^{-30}\times 2.5\times {10}^4$
$=8.5\times {10}^{-26}Nm$