List of top Questions asked in KEAM

A radioactive element with $6\times10^{5}$ atoms initially is left with $0.75\times10^{5}$ undecayed atoms in $48$ years. The half-life is:

In the hydrogen spectrum, the shortest wavelength of the Brackett series is produced during the transition:

An electron is accelerated from rest by 480 V, its wavelength is $\lambda$. If accelerated by 120 V, the wavelength is:

Which one of the following statements is INCORRECT regarding the photoelectric effect?

Light energy is redistributed in:

An unpolarized light incident on a plane glass surface gets totally polarized on reflection. If the refractive index of glass is $\tan 57^{\circ}$, then the angle of refraction is:

Chromatic aberration arises in thick lenses due to:

An electromagnetic wave travelling in vacuum has its electric field component, $E=15\sin(1.57y+5.4t)\hat{j}$. The wavelength of the wave is:

When a current changes at the rate of $30\ \text{A s}^{-1}$, the induced emf is $12\ \text{V}$. The self-inductance of the coil is:

If an inductor coil of self-inductance 2 H stores 25 J of magnetic energy, then the current I passing through it is:

Which one is not a ferromagnetic material?

Two charged particles of same mass but charges in ratio 1:4 enter a uniform perpendicular magnetic field. The ratio of their time periods is:

A coil having 100 turns and area $0.02\ \text{m}^{2}$ is placed perpendicular to a magnetic field of $1\ \text{Wb m}^{-2}$. The magnetic flux linked with the coil is:

A wire of $25\ \Omega$ resistance is cut into n pieces of equal length. If these pieces are connected in parallel, the equivalent resistance is $1\ \Omega$, then n is:

The resistance of a wire at $30^{\circ}\text{C}$ and $40^{\circ}\text{C}$ are respectively $5\ \Omega$ and $6\ \Omega$. The temperature coefficient of resistance is:

The value of R in the given circuit is:

The equivalent capacitance of n capacitors of equal capacitance when connected in series and parallel are respectively $0.4\ \mu F$ and $10\ \mu F$. The capacitance of each capacitor is:

A charge of 5 C is moved from a point P to another point Q by doing a work of 10 J. If the potential at P is 0.5 V, then the potential at Q is:

Which one of the following pairs of charges separated by the same distance r will experience a maximum force?

If the time period of a particle executing SHM is 8 s, then the time period of the potential energy of this particle is

A musician hits a drum 90 times in a minute. The time period of hit is

If the speed of the transverse wave in a wire under certain tension T is v, then its speed under tension $2T$ (in $ms^{-1}$) is

If the mean free path of a gas molecule at $27^{\circ}\text{C}$ is $10\times10^{-7}\ \text{m}$, its mean free path at $87^{\circ}\text{C}$ is:

The number of molecules contained in the gas of mass M is ($M_o$ - molar mass, $N_A$ - Avogadro's number)

Which one is INCORRECT statement?