List of top Physics Questions asked in KEAM

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

An air capacitor and identical capacitor filled with dielectric medium of dielectric constant 5 are connected in series to a voltage source of 12V. The fall of potential across $C_1$ and $C_2$ are respectively

The electric potential at a point at a distance r due to an eclectic dipole is proportional to

When two sound waves of slightly different ftequencies $f_1$ and $f_2$ are sounded together, then the time interval between successive maxima is

The velocity of a transverse wave propagating on a stretched string represented by the equation, $y = 0.5sin(x)(\frac{\pi}2 t + \frac{\pi}3 x)$ is (where x and y are in metres and / in seconds)

If the ratio of the acceleration due to gravity on the surface of earth to that on the surface of the moon is 6:1, then the ratio of the periods of a simple pendulum on their surfaces is

A planet with radius R and acceleration due to gravity g, will have atmosphere only if r.m.s. speed of air molecules is less than

The ratio of the kinetic energy values of 4g of hydrogen ($H_2$) to 7g of nitrogen ($N_2$) at room temprature is

When an ideal diatomic gas is heated at constant pressue, fraction of heat enerry supplied that increases the internal energy of the gas is

When the temperature of the source of a Carnot engine is at 400 K, its efficiency is 25%. The required increase in temperature of the source to increase the efficiency to 50% is