Search any question & find its solution
Question:
Answered & Verified by Expert
An electric dipole with dipole moment $4 \times 10^{-9} \mathrm{C}-\mathrm{m}$ is aligned at $30^{\circ}$ with the direction of a uniform electric field of magnitude $5 \times 10^4 \mathrm{NC}^{-1}$. Calculate the magnitude of the torque acting on the dipole.
Solution:
1184 Upvotes
Verified Answer
Given,
$$
\begin{aligned}
&\mathrm{p}=4 \times 10^{-9} \mathrm{C}-\mathrm{m} \\
&\mathrm{E}=5 \times 10^4 \mathrm{~N} \mathrm{C}^{-1} \ \\
&\theta=30^{\circ} \text { i.e. } \sin \theta=0.5, \tau=?
\end{aligned}
$$
By formula,
$$
\begin{aligned}
\tau &=\mathrm{pE} \sin \theta=4 \times 10^{-9} \times 5 \times 10^4 \times 0.5 \\
&=10^{-4} \mathrm{~J}(\text { or } \mathrm{Nm})
\end{aligned}
$$
$$
\begin{aligned}
&\mathrm{p}=4 \times 10^{-9} \mathrm{C}-\mathrm{m} \\
&\mathrm{E}=5 \times 10^4 \mathrm{~N} \mathrm{C}^{-1} \ \\
&\theta=30^{\circ} \text { i.e. } \sin \theta=0.5, \tau=?
\end{aligned}
$$
By formula,
$$
\begin{aligned}
\tau &=\mathrm{pE} \sin \theta=4 \times 10^{-9} \times 5 \times 10^4 \times 0.5 \\
&=10^{-4} \mathrm{~J}(\text { or } \mathrm{Nm})
\end{aligned}
$$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.