List of top Physics Questions

A point positive charge is brought near an isolated conducting sphere. The electric field is best given by

A positive charge $Q$ is uniformly distributed along a circular ring of radius $R$. A small test charge $q$ is placed at the centre of the ring as shown in figure. Then

A ring of radius R carries a charge Q, uniformly distributed along its circumference. What is the ratio of the electric field strength at a distance R to that at a distance $\frac{R}{\sqrt{2}}$ along the axis?

A rod of length $2.4\, m$ and radius $4.6\, mm$ carries a negative charge of $4.2 \times 10^{-7}\, C$ spread uniformly over it surface. The electric field near the mid-point of the rod, at a point on its surface is

A thin, metallic spherical shell contains a charge Q on it. A point charge q is placed at the centre of the shell and another charge $q_1$ is placed outside it as shown in figure. All the three charges are positive . The force on the charge at the centre is

A uniformly charged conducting sphere of $4.4\,m$ diameter has a surface charge density of $60\, \mu C\, m^{-2}$. The charge on the sphere is

An electron and a proton are situated in a uniform electric field. The ratio of their acceleration will be

A deuteron and an a-particle are placed in an electric field. If $F_1$ and $F_2$ be the forces acting on them and $a_1$ and $a_2$ be their accelerations respectively then, $a_1 = a_2$. Forces will be same in electric field.

Four point charges $q_1, q_2, q_3$ and $q_4$ are as shown in figure. The flux over the shown Gaussian surface depends only on charges $q_1$ and $q_2$. Electric field at all points on Gaussian surface depends only on charges $q_1$ and $q_2$.

In the absence of an external electric field, the dipole moment per unit volume of a polar dielectric is zero. The dipoles of a polar dielectric are randomly oriented.

Charge $q$ is uniformly distributed over a thin half ring of radius $R$. The electric field at the centre of the ring is

Coulomb?? law is true for

Debye is the unit of

Electric field lines provide information about

Electric lines of force about a negative point charge are

Figure below shows a closed surface which intersects a conducting sphere. If a positive charge is placed at the point P, the flux of the electric field through the closed surface

Figure shows electric field lines in which an electric dipole $\vec{p}$ is placed as shown. Which of the following statements is correct?

Five charges $q_1$, $q_2$, $q_3$, $q_4$ and $q_5$ are fixed at their positions as shown in figure. $S$ is Gaussian surface. The Gauss?? law is given by $\oint_{_{_s}}\vec{E}\cdot\vec{ds}=\frac{q}{\varepsilon_{0}}$. Which of the following statements is correct?

Five styrofoam balls are suspended from insulating threads. Several experiments are performed on the balls and the following observations are made - (i) Ball A repels C and attracts B (ii) Ball D attracts B and has no effect on E (iii) A negatively charged rod attracts both A and E. An electrically neutral styrofoam ball gets attracted if placed nearby a charged body due to induced charge. What are the charges, if any, on each ball?

Four point charges are placed at the corners of a square $ABCD$ of side $10\, cm$, as shown in figure. The force on a charge of $1\,\mu C$ placed at the centre of square is

If $10^9$ electrons move out of a body to another body every second, then the time required to get a total charge of $1\,C$ on the other body is

If a body is charged by rubbing it, its weight

If a body is positively charged, then it has

If an electron has an initial velocity in a direction different from that of an electric field, the path of the electron is

In a medium of dielectric constant K, the electric field is $\vec{E}$ . If $\in_0$ is permittivity of the free space, the electric displacement vector is