An electric dipole of moment 
is lying along a unifrom electric field 
. The work done in rotating the dipole by 90° is:
A
pE
B
C
2pE
D
pE
Text Solution
Verified by ExpertsThe correct answer is:
D
When an electric dipole is placed in an electric field 
, torque 
= 
. 
acts on it. This torque tries to rotate the dipole through an angle.
If the dipole is rotated from an angle θ 1 to θ 2 . then work done by external force is given by
w = pE (cos θ 1 – cos θ 2 ) … (i)
putting θ 1 = 0°, θ 2 = 90° in the Eq. (i), we get
w = pE (cos 0° – cos 90°)
= pE (1 – 0) = pE
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
A charge q is placed at the center of the line joining two equal charges Q. The system of the three…
Inside a hollow charged spherical conductor, the potential
Two small spheres each carrying a charge q are placed r meter apart. If one of the spheres is taken…
The electric charge in uniform motion produces
Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. No current will flow, if…
The electric field inside a spherical shell of uniform surface charge density is