List of top Physics Questions

The effective capacity between a and b in the figure given is 

effective capacity 

find x.

Consider the circuit shown in the figure. Find the charge on capacitor C between A and D in a steady state.

A hundred-turn closely wound circular coil, of main radius 10 cm, carries a current of 3.2A. The coil is placed in a vertical plane and is free to rotate about a horizontal direction which coincides with its diameter. uniform magnetic field of 2T, in the horizontal direction, exists such that initially the axis of the coil is in the direction of the field the call rotates through an angle of 90\(^{\circ}\) under the influence of the magnetic field. calculate the torque in the initial and final position of the coil.

If the value of the potential gradient on the potentiometer wire is decreased, then the new null point will be obtained at

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to

a capacitor of 20 microfarads charged to 500v is connected in parallel with another capacitor of 10\(\mu F\) charged to 200V.Find the common potential.

can an object be in pure translation as well as in pure rotation?

a wire of 15 ohm resistance is gradually stretched to twice its length.It is then cut into two equal parts.these parts are then connected in parallel across a 3.0V battery.Find the current drawn from he battery.

Consider the situation shown in Fig. The two slits S1 and S2 placed symmetrically around the central line are illuminated by monochromatic light of wavelength λ. The separation between the slit is d. The light transmitted by the slits falls on a screen S0 placed at a distance D from the slits. The slit S3 is at the central line and the slit S4 is at a distance z from S3 Another screen Sc is placed a further distance D away from Sc Find the ratio of the maximum to minimum intensity observed on Sc

If \(z=\frac{\lambda D}{2d}\)
capacity of parallel plate capacitor vanes directly as nth power of the distance between two plates. value of n is
 
Which of the following time measuring devices is most precise ?

The SI unit of electric flux is

An electric dipole, consisting of two opposite charges of $2 \times 10^{-6} \, C$ each separated by a distance 3 cm is placed in an electric field of $2 \times 10^5 \, N/C$. Torque acting on the dipole is
A polythene piece rubbed with wool is found to have a negative charge of $6 \times 10^{-7}\, C$. The number of electrons transferred to polythene from wool is
The electric field at a point is
A projectile is fired from the surface of the Earth of radius $R$ with a velocity $\eta v_{e}$ , where $v_{e}$ is the escape velocity and $\eta < 1$ . Neglecting the air resistance, the orbital velocity of the projectile is
The number density of electrons and holes in pure silicon at $27 ^{\circ}C$ are equal and its value is $2.0 \times 10^{16}\, m^{-3}$. On doping with indium the hole density increases to $4.5 \times 10^{22}\, m^{-3}$, the electron density in doped silicon is
A solid sphere of volume $V$ and density $\rho$ floats at the interface of two immiscible liquids of densities $\rho_1$ and $\rho_2$ respectively. If $\rho_1$ < $\rho_2$ < $\rho_3$, then the ratio of volume of the parts of the sphere in upper and lower liquid is
A ray incident at a point at an angle of incidence of $60^{\circ}$ enters a glass sphere of refractive index $\sqrt{3}$ and is reflected and refracted at the farther surface of the sphere. The angle between the reflected and refracted rays at this surface is
Electric potential is :
Electric intensity is equal to :
Electric field on the axis of a small electric dipole at a distance $r$ is $\overrightarrow{ E }_{1}$ and $\overrightarrow{ E }_{2}$ at a distance $2 r$ on a line of perpendicular bisector. Then
A solid sphere of uniform density and radius $R$ applies a gravitational force of attraction equal to $F_{1}$ on a particle placed at $P$ , distance $2 \, R$ from the centre O of the sphere. A spherical cavity of the radius $R/2$ is now made in the sphere as shown in the figure. The sphere with the cavity now applies a gravitational force $F_{2}$ on the same particle placed at $P$ . The ratio $F_{2}/F_{1}$ will be
A radioactive nucleus undergoes a series of decay according to the scheme $ {A ->[\alpha] A1}$$ { ->[\beta] A2}$$ { ->[\alpha] A3}$$ { ->[\gamma] A4}$ If the mass number and atomic number of A are 180 and 72 respectively, these numbers of $A_4$ are
The equivalent resistance of the circuit, across $AB$ is given by