List of top Questions asked in KEAM

A transistor amplifier along with a tank circuit with positive feedback will act as
In p-type semiconductors
If the mass numbers of two nuclei are in the ratio 3: 2, then the ratio of their nuclear densities is :
The ratio of the total energy E of the electron to its kinetic energy K in hydrogen atom is
1018 fissions per second is required for producing power of 300 MW in a nuclear power station. To increase the power output to 360 MW the additional number of fissions required per second is
During $ẞ^{-}$ decay of a radioactive element there is an increase in its
If the momentum of an α-particle is half that of a proton, then the ratio between the wavelengths of their de-Broglie waves is
If $θ_p$ is the polarizing angle for a glass plate of refractive index μ and critical angle $θ_c$, then
In Young's double-slit experiment, two different light beams of wavelengths $λ_1$ and $λ_2$ produce interference pattern with band widths $β_1$ and $β_2$ respectively. If the ratio between $β_1$ and $β_2$ is 3:2, then the ratio between and is
An object is placed at 10 cm in front of a concave mirror. If the image is at 20 cm from the mirror on the same side of the object, then the magnification produced by the mirror is
The apparent depth of a needle lying in a water beaker is found to be 9 cm. If water is replaced by a liquid of refractive index 1.5, then the apparent depth of needle will be (μ of water is 4/3)
Fresnel distance for an aperture of size a illuminated by a parallel beam of light of wavelength λ, deciding the validity of ray optics is
In an electromagnetic wave, the oscillating electric and magnetic field vectors are oriented in
Electromagnetic waves against their detection devices are matched below. The mismatch is
The total intensity of earth's magnetic field at the poles is 7 units. Its value at the equator is
Among vadous circuits coDstructed with rcsistor _R, inductor _L and capacitor C, the cicuit that gives maximum power dissipation is
If air core is replaced by an iron core in an inductor, its self-inductance is increased from 0.02 mH to 40 mH. The relative permeabiliry of iron is
If $B_c$ is the magnetic induction at the ceflte ofa circular coit carrying curreflt, then the magnetic induction at a poitrt oo the axis of the coil at a distance equal to the radius of the coil is
The hard ferromagnetic material among the following is
In Cyclotron, the frequency of revolution ofthe charged particle in a magnetic field is independent of
A current carrying coil placed in a magnetic field B experiences a torque τ. If θ is the angle between the normal to the plane of the coil and field B and φ is the flux linked with the coil, then
A conductor of length 20 cm carrying a curent of 5A is placed at an angle of 30° to the extemal magnetic field of 0.5 T. The.force acting on it is
A Wheatstone network is balanced with respective resisto$ 5Ω. l0Ω. 20 Ω and 40 Ω in tbe P. 0. R and S arms. If a 40 Ω) resisror is connecred across S arm. Then the bridge is again balanced by connecting
The magnitude of tfie drift velocity per unit electric field is defined as
The ratio of the magnitudes of electrostatic force between two protons at a distarce r apart to that between two electrons at the same distance of separation is