List of top Questions asked in KEAM

If N is the initial number of atoms in a radioactive sample, then the number of atoms decayed after the five half life periods is

In a hydrogen atom, the transition of an electron from the energy level, \(n_2 = \infty\) and \(n_1 = 3\) is the

If light waves of wavelengths \(\lambda\) and \(\lambda/3\) are incident on the surface of a material, photoelectrons are emitted with maximum kinetic energy E and 4E respectively, then the work function of the material is

The distance of an object placed in front of a concave mirror of radius of curvature 24 cm that gives its magnification as 3 is

The ratio of the speed of light in vacuum to that in a medium is called

If light waves of wavelengths \(\lambda\) and \(\lambda/3\) are incident on the surface of a material, photoelectrons are emitted with maximum kinetic energy \(E\) and \(4E\) respectively, then the work function of the material is

In Young's double slit experiment using a source of wavelength \(\lambda\) interference bands are observed on a screen. If the separation between the slits alone is halved in this experiment, then the angular separation \(\omega\) of the fringes on the screen becomes

The mismatched pair regarding the induced emf is

If an electric bulb of resistance \(400 \Omega\) is connected to an ac source of peak voltage 282.8 V, then the electric power of the bulb is

The velocity of light in a medium of relative permittivity 2 and relative permeability 4.5 is (velocity of light in free space is c)

If a rectangular loop carrying a current I and area ab is placed such that a uniform magnetic field B is in the plane of the loop, then the magnitude of torque on it is

The diamagnetic and paramagnetic materials at 300 K are respectively,

If \(\tau\) is the average time between any two successive collisions for the electrons in a metal wire under the application of an electric field E, then the mobility \(\mu\) of the electrons is

According to Biot-Savart's law, the magnetic field B is

The maximum current drawn from a battery of 12 V with internal resistance of \(0.5 \Omega\) is

Three identical resistors are connected in the form of a triangular mesh ABC. If a battery of 12 V is connected across AB, then the ratio of the current flowing through AB to that through ACB is

Two identical isolated capacitors A and B are charged so that each has a charge of 4C. If a charge of \(-2C\) is added to A and \(+2C\) to B, then the ratio of respective potentials is

If the torque acting on an electric dipole when placed at an angle \(30^{\circ}\) with the direction of a uniform electric field is \(\tau\), then the torque acting on the same dipole when placed in the same field at an angle \(45^{\circ}\) is

A conductor with an air core cavity inside, is charged to attain the surface charge density of \(\sigma\). If E is the magnitude of electric field and V is the potential, then inside the cavity

If a diode is forward biased, then the

The band gap energy of silicon is

When a radioactive material emits an \(\alpha\)-particle, its position in the periodic table

A convex lens having power \(P\) is cut into two halves perpendicular to the principal axis. Then the power of each piece is

In a plane electromagnetic wave, the magnetic field is given by \(B = 400 \times 10^{-6}\sin[(4.0 \times 10^{-4})(t - x/c)]\). The peak value of electric field (in V m\(^{-1}\)) is

In Young’s double slit experiment performed in air medium, the fringe width observed is 1.4 mm. If the entire arrangement is kept in a liquid medium of refractive index 1.4, then the fringe width (in mm) will be