Question

An electric dipole, consisting of two opposite charges of magnitude $2\times {10}^{-6}$ C each separated by a distance 3 cm is placed in an electric field of magnitude $2\times {10}^5$ N/C along the direction making ${90}^0$ with the field. Torque acting on the dipole is :

• A. $12\times {10}^{-1}Nm$
• B. $12\times {10}^{-2}Nm$
• C. $12\times {10}^{-3}Nm$
• D. $12\times {10}^{-4}Nm$

Answer 1

The correct option is C $12\times {10}^{-3}Nm$

Given data,

$Charges\left(q\right)=2\times {10}^{-6}C,$

$Distance\left(d\right)=3cm=3\times {10}^{-2}m$

$electricfield\left(E\right)=2\times {10}^{5}N/C.$

$Torque\left(\tau \right)=?$

We know that

$Torque\left(\tau \right)$ to be measured

$Torque=charge\times distance\times Electricfield$

$Torque\left(\tau \right)=(2\times {10}^{-6})\times (3\times {10}^{-2})\times (2\times {10}^5)$

$=12\times {10}^{-3}Nm$