List of top Physics Questions

One-fourth length of a spring of force constant k is cut away. The force constant of the remaining spring will be

A pendulum has time period $T$ in air when it is made to oscillate in water, it acquired a time period $T =\sqrt{2} T$. The density of the pendulum bob is equal to (density of water $=1$ )

The time period of the variation of potential energy of a particle executing $SHM$ with period $T$ is

Under the action of a given coulombic force the acceleration of an electron is $2.5 \times 10^{22}\, m \,s^{-2}$. Then the magnitude of the acceleration of a proton under the action of same force is nearly

An electron initially at rest falls a distance of $1.5\, cm$ in a uniform electric field of magnitude $2 \times 10^4\, N/C$. The time taken by the electron to fall this distance is

Charge $Q$ is distributed over a ring, then the force on charge $q$ placed at the centre of the ring will be

The figure shows some of the electric field lines corresponding to an electric field, The figure suggests

The distance between two charges $6\,\mu\,C$ and $15\,\mu\,C$ is $2\,m$. At what point on the line joining the two, the intensity will be zero?

A ball with charge $50 \,e$ is placed at the centre of a hollow spherical shell which has a net charge of $- 50\,e$ . What is the charge on the shells outer surface?

A charged particle is free to move in an electric field. It will travel

An electron moving with the speed $5 \times 10^{6}$ per sec is shooted parallel to the electric field of intensity $1 \times 10^{3} \,N / C$. Field is responsible for the retardation of motion of electron. Now evaluate the distance travelled by the electron before coming to rest for an instant (mass of $e=9 \times 10^{-31} \,kg$, charge $\left.=1.6 \times 10^{-19} \,C \right)$

Let $E_{a}$ be the electric field due to a dipole in its axial plane distant $1$ and let $E _{ q }$ be the field in the equitorial plane distant $1 '$. The relation between $E _{ a }$ and $E _{q}$ is

Two identical conducting balls $A$ and $B$ have positive charges $q_1$ and $q_2$ respectively but $q_1 \ne q_2$ The balls are brought together so that they touch each other and then kept in their original positions. the force between them is

The electric flux for Gaussian surface $A$ that encloses the charged particles in free is (Given $q_1, = - 14 \, n \, C, q_2 = 78.85 \, n \, C, \, q_3 = - 56 \, n \, C) $

Electric field produced by an electron at a point is $E$. What will be electric field produced by $Li^{+++}$ at the same point if it is placed at position of electron ?

Let there be a spherically symmetric charge distribution with charge density varying as $\rho\left(r\right) = \rho_{0} \left(\frac{5}{4}-\frac{r}{R}\right)$ upto $r = R$, and $\rho \left(r\right) = 0$ for $r > R$, where r is the distance from the origin. The electric field at a distance $r\left(r < R\right)$ from the origin is given by

Two charged spherical conductors of radii $ {{R}_{1}} $ and $ {{R}_{2}} $ are connected by a wire. Then the ratio of surface charge densities of the spheres $ {{\sigma }_{1}}/{{\sigma }_{2}} $ is

Two point charges $-q$ and $+q/2$ are situated at the origin and at the point $(a, 0, 0)$ respectively. The point along the $X$-axis where the electric field vanishes is

With the increase of temperature, the surface tension of the liquid

The kinetic energy of an electron, which is accelerated in the potential difference of 100 V, is

An $8\, \mu F$ capacitor is connected across $220\,V, 50 \,Hz $ line. What is the peak value of the charge through capacitor?

0.2 F capacitor is charge to 600 V by a battery, on removing the battery, it is connected with another parallel plate condenser of I F . The potential decreases to

A number of condensers, each of the capacitance $1 \, \mu F$ and each one of which gets punctured if a potential difference just exceeding $500 \,V$ is applied, are provided. An arrangement suitable for giving capacitance of $2 \, \mu F$ across which $3000 \,V $ may be applied requires at least

Two point-charges $ \pm 10\mu C $ are placed $ 5.00\,mm $ apart, forming an electric dipole. Compute electric field at a point on the axis of the dipole $ 15\,cm $ away from the centre on a line passing through the centre dipole.

An uncharged capacitor with a solid dielectric is connected to a similar air capacitor charged to a potential of $V_0$. lf the common potential after sharing of charges becomes V, then the dielectric constant of the dielectric must be