List of top Physics Questions asked in KEAM

When a PN junction diode is forward biased, the CORRECT statement is

Which of the following can be used in the output circuit of a diode rectifier to filter ac ripples?

The mass of a proton is $1.0073\text{u}$ and that of a neutron is $1.0087\text{u}$. The binding energy of $_2^4\text{He}$ is approximately (Given: helium nucleus mass = $4.0015\text{u}$)}

The ratio of the longest wavelength of the Lyman series to that of Ballmer series of the hydrogen spectrum is

The work function of a material is $6.6 \text{ eV}$. Then, the threshold wavelength of the metal is approximately (Take $h = 6.6 \times 10^{-34} \text{J.s}$)}

An electron and a proton possess same kinetic energy. If the de Broglie wavelengths of the electron and the proton are $\lambda_e$ and $\lambda_p$ respectively, identify the CORRECT relation.

The primary purpose of using polaroids in sunglasses is to

The width of a fringe is $0.5 \text{ mm}$ in Young’s double slit experiment for a light of wavelength $500\text{ nm}$. If the wave length of light alone is changed to $600 \text{ nm}$, the width of the fringe becomes}

A biconvex lens with equal radii of curvature $R$ has a focal length $f$. If the refractive index of the lens is $\frac{3}{2}$, the focal length of the lens is

The CORRECT statement among the following regarding electromagnetic waves is

The transformer core is laminated in order to

A current of $2 \text{ A}$ produces a magnetic flux of $10^{-3}$ weber per turn in a coil of $1000$ turns. Then, the self-inductance of the coil is

The INCORRECT statement is

The current through a galvanometer of resistance $50 \Omega$ is only $4\%$ of the main current when a shunt resistance is connected. The value of the shunt resistance is approximately

A wire of length $6 \text{ m}$ is bent to form a circular loop of single turn. If the current through the loop is $2 \text{ A}$, the magnetic moment of the circular loop (in $\text{Am}^2$ ) is

A particle of charge 10 times that of an electron is revolving in a circular path of radius $0.5 \text{ m}$. If the frequency of rotation is 10 rotations per second, the magnetic field at the centre of the circular path is approximately ($\mu_0 = 4\pi \times 10^{-7} \text{ Hm}^{-1}$)}

Kirchhoff’s first and second laws are respectively based on the conservation of

A battery supplies $0.6 \text{ A}$ current when a $3 \Omega$ resistor is connected with it. When the resistor $3 \Omega$ is replaced by $6 \Omega$, the current is reduced to $0.4 \text{ A}$. Then, the internal resistance of the battery is

A uniform wire of area of cross section $1 \times 10^{-7} m^2$ carries a current of $1.6 \text{ A}$. If the number density of electrons is $5 \times 10^{28} m^{-3}$, the drift velocity of electrons (in $\text{mm s}^{-1}$) is

Two air core capacitors of equal capacitance $C$ are connected in series. If one of them is filled with a dielectric substance of dielectric constant $k$, the effective capacitance becomes

An electric dipole is placed at an angle of $30^\circ$ with an electric field intensity $3 \times 10^5 \text{ NC}^{-1}$ experiences a torque $3 \text{ Nm}$. If the length of dipole is $2 \text{ cm}$, the charge on the dipole is (in milli coloumb)}

A proton travels through a distance of $5\text{ m}$ in the direction of uniform electric field of intensity $4\text{ NC}^{-1}$. The work done on the proton by the electric field is

Two metallic spheres of radii in the ratio 1 : 2 are charged and joined by a connecting wire. The ratio of electric field intensities at the surfaces of the spheres is

In the given wave equation $y=0.05 \sin \frac{2\pi}{\lambda}(x-200t)\text{ m}$, the velocity of the wave (in $\text{ms}^{-1}$) is

When an open pipe is suddenly closed at one end, the frequency of the third harmonic of the closed pipe is found to be $50\text{ Hz}$ more than the fundamental frequency of the open pipe. The fundamental frequency of the open pipe is