ABC is an equilateral triangle. Charges +q are placed at each corner. The electric intensity at O will be 

(1) $\frac{1}{4\pi {\epsilon }_0}\frac{q}{r^2}$

(2) $\frac{1}{4\pi {\epsilon }_0}\frac{q}{r}$

(3) Zero

(4) $\frac{1}{4\pi {\epsilon }_0}\frac{3q}{r^2}$

A metallic solid sphere is placed in a uniform electric field. The lines of force, as shown in the figure, follow the path(s): 

1. \(1\)

2. \(2\)

3. \(3\)

4. \(4\)

The figure shows the electric lines of force emerging from a charged body. If the electric field at \(A\) and \(B\) are \(E_A\) and \(E_B\) respectively and if the displacement between \(A\) and \(B\) is \(r,\) then:

1. \(E_A>E_B\)
 2. \(E_A<E_B\)
 3. \(E_{A} = \frac{E_{B}}{r}\)
 4. \(E_{A} = \frac{E_{B}}{r^{2}}\)$\frac{{\mathrm{}}^{}}{}$

What is the flux through a cube of side a if a point charge of q is a one of its corner?

1. $\frac{2q}{{\epsilon }_0}$                                         

2. $\frac{q}{8{\epsilon }_0}$

3. $\frac{q}{{\epsilon }_0}$                                         

4. $\frac{q}{2{\epsilon }_0}6a^2$

A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will

1. be reduced to half                                 

2. remain the same

3. be doubled

4. increase four times

An electric dipole of moment p is placed in an electric field of intensity E. The dipole acquires a position such that the axis of the dipole makes an angle $\theta$ with the direction of the field. Assuming that the potential energy of the dipole to be zero when $\theta =90°$, the torque and the potential energy of the dipole will respectively be

1. $pE \sin \theta ,-pE \cos \theta$

2. $pE \sin \theta ,-2pE \cos \theta$

3. $pE \sin \theta ,2pE \cos \theta$

4. $pE \cos \theta ,-pE \sin \theta$

Which of the following graphs shows the variation of electric field \(E\) due to a hollow spherical conductor of radius \(R\) as a function of distance from the centre of the sphere?

1.		2.
3.		4.

\(q_1, q_2, q_3~\text{and}~q_4\) are point charges located at points as shown in the figure and \(S\) is a spherical Gaussian surface of radius \(R\). Which of the following is true according to the Gauss’s law?

The dimension of (1/2) ${\epsilon }_0{E}^2 ({\epsilon }_0$: permittivity of free space; E: electric field) is

(1) MLT^–1

(2) ML²L^–2

(3) ML^–1T^–2

(4) ML²T^–1