Two non-conducting spheres of radii $R_1$ and $R_2$ and carrying uniform volume charge densities $+\rho$ and $-\rho ,$ respectively, are placed such that they partially overlap, as shown in the figure. At all points in the overlapping region :

Charges $Q, 2Q$ and $4Q$ are uniformly distributed in three dielectric solid spheres $1, 2$ and $3$ of radii $\frac{R}{2}, R$ and $2R$ respectively, as shown in figure. If magnitudes of the electric fields at point $P$ at a distance $R$ from the centre of spheres $1, 2$ and $3$ are $E_1, E_2$ and $E_3$ respectively, then :-

Assertion : A point charge a is placed at centre of spherical cavity inside a spherical conductor as shown. Another point charge $Q$ is placed outside the conductor as shown. Now as the point charge $Q$ is pushed away from conductor, the potential difference $\left(V_A-V_B\right)$ between two points $A$ and $B$ within the cavity of sphere remains constant.

Reason : The electric field due to charges on outer surface of conductor and outside the conductor is zero at all points inside the conductor.

Assertion: A solid uncharged conducting cylinder moves with acceleration $\mathrm{a}$ (w.r.t ground). As a result of the acceleration of the cylinder, an electric field is produced within a cylinder.

Reason: When a solid conductor moves with acceleration a then from a frame of conductor a pseudo force (of magnitude $ma;$ where $m$ is mass of electron) will act on free electrons in the conductor. As a result, some portion of the surface of the conductor acquires a negative charge and a remaining portion of a surface of conductor acquires a positive charge.

Assertion: Two concentric conducting spherical shells are charged. The charge on the outer shell is Varied keeping the charge on the inner shell constant, as a result, the electric potential difference between the two shells does not change.

Reason: If the charge is changed on a thin conducting spherical shell, the potential at all points inside the shell changes by the same amount.

Assertion: The electric potential and the electric field intensity at the centre of a square having four point charges at their vertices (as shown) are zero.

Reason: Electric field is a negative derivative of the potential.

Assertion: No two electric lines of force can intersect each other.

Reason: Tangent at any point of electric line of force gives the direction of electric field.

Assertion : Positive charge always moves from a higher potential point to a lower potential point.

Reason : Electric potential is a vector quantity.

Assertion: On going away from a point charge or a small electric dipole, the electric field decreases at the same rate in both cases.

Reason: Electric field is inversely proportional to the square of the distance from the charge in all cases.