Advertisements
Advertisements
प्रश्न
An electric dipole of length 2 cm, when placed with its axis making an angle of 60° with a uniform electric field, experiences a torque of \[8\sqrt{3}\] Nm. Calculate the potential energy of the dipole, if it has a charge \[\pm\] 4 nC.
Advertisements
उत्तर
Torque, \[\tau = \text { PE sin }\theta = \left( Ql \right)\text { E sin }\theta\] ........ (1)
Here, l is the length of the dipole, Q is the charge and E is the electric field.
Potential energy,
\[\text { U = - P Ecos }\theta = - \left( Ql \right)\text {Ecos}\theta\]
Dividing (2) by (1):
\[\frac{\tau}{U} = \frac{\left( Ql \right)E\sin\theta}{- \left( Ql \right)E\cos\theta} = - \tan\theta\]
\[ \Rightarrow U = - \frac{\tau}{\tan\theta}\]
\[ \Rightarrow U = - \frac{\tau}{\tan {60}^o}\]
\[ \Rightarrow U = - \frac{8\sqrt{3}}{\sqrt{3}}\]
\[ \Rightarrow U = - 8 J\]
APPEARS IN
संबंधित प्रश्न
An electric dipole of length 1 cm, which placed with its axis making an angle of 60° with uniform electric field, experience a torque of \[6\sqrt{3} Nm\] . Calculate the potential energy of the dipole if it has charge ±2 nC.
Define dipole moment of an electric dipole. Is it a scalar or a vector?
An electric dipole is placed at the centre of a sphere. Mark the correct options.
(a) The flux of the electric field through the sphere is zero.
(b) The electric field is zero at every point of the sphere.
(c) The electric field is not zero anywhere on the sphere.
(d) The electric field is zero on a circle on the sphere.
Two particles A and B, of opposite charges 2.0 × 10−6 C and −2.0 × 10−6 C, are placed at a separation of 1.0 cm. Calculate the electric field at a point on the perpendicular bisector of the dipole and 1.0 m away from the centre.
Polar molecules are the molecules ______.
Polar molecules are the molecules ______.
A square surface of side l (m) in the plane of the paper. A uniform electric field E(V/m) also in the plane of the paper is limited only to the lower half of the square surface, the electric flux (in SI units) associated with the surface is ______.
Eight dipoles of charges of magnitude e each are placed inside a cube. The total electric flux coming out of the cube will be ______.
In an electric dipole, what is the locus of a point having zero potential?
