List of top Physics Questions

Application of a forward bias to a $p-n$ junction

A network of four capacitors of capacities equal to $C_{1}=C, C_{2}=2 C, C_{3}=3 C$ and $C_{4}=4 C$ are connected to a battery as shown in the figure.

The ratio of the charges on $C_{2}$ and $C_{4}$ is

The work functions for metals $A, B$ and $C$ are respectively $1.92\, eV,\, 2.0\, eV$ and $5\, eV$. According to Einstein's equation, the metal(s) which will emit photoelectrons for a radiation of wavelength $4100\,?$ is/are

A force $F$ is applied on the wire of radius $r$ and length $L$ and change in the length of wire is $l$. If the same force $F$ is applied on the wire of the same material and radius $2\, r$ and length $2\, L$, then the change in length of the other wire is

A $1\, kg$ stone at the end of $1\, m$ long string is whirled in a vertical circle at constant speed of $4\, m / s$. The tension in the string is $6\, N$, when the stone at $\left(g=10\, m / s ^{2}\right)$

The core of any transformer is laminated so as to

A nucleus of mass $M + \Delta m$ is at rest and decays into two daughter nuclei of equal mass $\frac{M}{2}$ each. Speed of light is c The binding energy per nucleon for the parent nucleus is $E_1$ and that for the daughter nuclei is $E_2$. Then

Light rays from a luminous (bright point) object in a denser medium of refractive index n at a depth h, outline a circle of radius equal to the depth, at the interface. The refractive index of denser medium is

In Young's double slit experiment, intensities at a bright fringe is $I$. When one of the slits is dosed, intensity at the same position is

Decrease in wavelength as a result of scattering is observed in

A black body emits maximum energy at wavelength $\lambda_0$ when temperature is $T_1$. At temperature $T_2$, it emits maximum energy at $\frac{4}{5} \lambda_0$? Ratio of the two temperature $T_1: T_2$ is

Weight of a body

A plano-convex lens $(f = 20 cm)$ is silvered at plane surface. Now focal length will be

The centre of mass of three particles of masses 1 kg, 2 kg and 3 kg is at (3, 3, 3) with reference to a fixed coordinate system. Where should a fourth particle of mass 4 kg be placed, so that the centre of mass of the system of all particles shifts to a point (1, 1, 1)?

The angular width of the central maximum of the diffraction pattern in a single slit of width a experiment, with $ \lambda $ as the wavelength of light, is

Light is an electromagnetic wave. Its speed in vacuum is given by the expression

Which of the following is the smallest unit ?

A particle of mass $ 100\,g $ is thrown vertically upwards with a speed of $5m/s $ . the work done by the force of gravity during the time the particle goes up is

At what angle must the two forces (x + y) and (x - y) act so that the resultant may be $\sqrt{x^2 + y^2}$ ?

A spring of force constant 800 N$m^{-1}$ has an extension of 5 cm. The work done in extending it from 5 cm to 15 cm is

A radioactive material decays by simultaneous emission of two particles with half-lives 1620 yr and 810 yr respectively. The time in year after which one-fourth of the material remains, is

A proton enters a magnetic field of flux density $1.5 \,Wb / m ^{2}$ with a speed of $2 \times 10^{7} m / s$ at angle of $30^{\circ}$ with the field. The force on a proton will be

If the moment of inertia of a disc about an axis tangential and parallel to its surface be $I$, then what will be the moment of inertia about the axis tangential but perpendicular to the surface?

A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is