NEET Questions

A solid sphere of uniform density $\rho$ and radius $R$ has a concentric spherical cavity of radius $R/2$. The gravitational field at a distance $r = R/4$ from the center is:

A uniformly charged non-conducting sphere of radius $R$ and charge $Q$ has electric potential $V_0$ at its center. If a spherical cavity of radius $R/2$ is carved out symmetrically, such that the center of the cavity is at a distance $R/2$ from the center of the sphere, what is the electric potential at the center of the cavity?

Two point charges +q and -2q are placed a distance 'd' apart. At what distance along the line joining the two charges is the electric potential zero?

Two concentric conducting spherical shells of radii $R_1$ and $R_2$ ($R_2 > R_1$) carry charges $Q_1$ and $Q_2$ respectively. The potential difference between the shells is:

Two identical short bar magnets, each of magnetic moment $M$, are placed perpendicular to each other at a distance $d$ apart. The magnetic field at a point midway between them on the line joining their centers is:

Two short bar magnets of magnetic moments 'M' each are arranged at the opposite corners of a square of side 'd' such that their centres coincide with the corners and their axes are parallel. If the like poles are in the same direction, the magnetic induction at any of the other corners of the square is:

Two point charges +q and -q are separated by a distance d. What is the electric field at the midpoint between them?

An infinitely large non-conducting sheet has a uniform surface charge density $\sigma$. A small circular hole of radius 'a' is cut in the sheet. What is the electric field at a point P on the axis of the hole, a distance 'z' away from the center of the hole?

A non-conducting infinitely long solid cylinder of radius 'R' has a uniform volume charge density $\rho$. A spherical cavity of radius 'R/2' is scooped out with its center lying on the axis of the cylinder as shown. If $E_1$ is the magnitude of the electric field at point P (at a distance 'r' from the center of the cavity along the perpendicular bisector of the line joining the center of the cylinder and the center of the cavity where $r > R$) and $E_2$ is the magnitude of the electric field at point Q (at a radial distance 'R/2' from the center of the cavity within the cavity), the ratio $E_1/E_2$ is:

Two long parallel wires carry currents $I_1$ and $I_2$ in the same direction. The wires are separated by a distance $d$. A point $P$ lies in the plane of the wires at a distance $x$ from one wire and $(d-x)$ from the other. Where should $P$ be located so that the net magnetic field is zero?