List of top Physics Questions

Kirchhoff's first law ie, $\Sigma i=0$ at a junction is based on the law of conservation of
A wire of resistance $9 \Omega$ is uniformly stretched such that.its radius becomes $1/3$ of the original radius. Ratio of the new to old resistance is
The unit of specific conductivity is
A moving coil galvanometer is converted into an ammeter reading up to $0.03 \,A$ by connecting a shunt of resistance $4r$ across it. and into an ammeter reading up to $0.06 \,A$ when a shunt of resistance $r$ is connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used?
The reading of the ammeter in the following figure will be
A voltmeter of resistance $ 1000\,\Omega $ gives full scale deflection when a current of $ 100\,mA $ flows through it. The shunt resistance required across it to enable it to be used as an ammeter reading $ 1\,A $ at full scale deflection is
A pure semiconductor has negative temperature coefficient of resistance. On raising the temperature, more charge carriers are released, conductance increases and resistance decreases.
The magnitude and direction of current $ I $ (in $A$) Indicated in the following circuit is
An electric motor operating on $15\,V$ supply draws a current of $5 \,A$ and yields mechanical power of $60 \,W$. The energy lost as heat in one hour (in $ kJ$ ) is
Two cells of emf $ E_1 $ and $ E_2(E_1 > E_2) $ are connected as shown in figure. When a potentiometer is connected between A and B, the balancing length of the potentiometer wire is 300cm . On connecting the same potentiometer between A and C, the balancing length is 100 cm. The ratio $ \frac{E_1}{E_2} $ is
For a particle in $ SHM $ , if the amplitude of the displacement is a and the amplitude of velocity is $ v $ , the amplitude of acceleration is
The average acceleration of a particle performing $ SHM $ over one complete oscillation is
A particle is vibrating in a simple harmonic motion with an amplitude of $4 \,cm$. At what displacement from the equilibrium position, is its energy half potential and half kinetic?
A clock $S$ is based on osculation of a spring and a clock $P$ is based on pendulum motion. Both clocks run at the same rate on earth. On a planet having the same density as earth but twice the radius
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 $=1$ )
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
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 $\left.=1.6 \times 10^{-19} \,C \right)$