List of top Questions asked in KEAM- 2025

In which of the following reactions does entropy decrease? (i) $2Pb(NO_{3})_{2(s)}\rightarrow 2PbO_{(s)}+4NO_{2(g)}+O_{2(g)}$ (ii) $H_{2}O_{(g)}\rightarrow H_{2}O_{(l)}$ (iii) $Br_{2(l)}\rightarrow 2Br_{(g)}$ (iv) $C_{6}H_{6(l)}\rightarrow C_{6}H_{6(s)}$
The enthalpy of combustion values of $C_{2}H_{4(g)}$, $C_{(graphite,s)}$ and $H_{2(g)}$ are respectively $-1411\ \text{kJ mol}^{-1}$, $-394\ \text{kJ mol}^{-1}$ and $-286\ \text{kJ mol}^{-1}$. What is the enthalpy of formation of $C_{2}H_{4(g)}$ in $\text{kJ mol}^{-1}$?
A p-n junction diode without any voltage biasing acts as:
The possible number of energy states in a Ge crystal containing $5\times10^{3}$ atoms is:
A sub-atomic particle of mass $6.63\times10^{-31}\ \text{kg}$ is moving with a velocity of $1\times10^{6}\ \text{m s}^{-1}$. What is the de Broglie wavelength (in nm) associated with it ($h=6.63\times10^{-34}\ \text{J s}$)?
For hydrogen atom, the orbitals with the lowest energy among the given orbitals are: (i) $4s$ (ii) $2p_x$ (iii) $3d_{z^2}$ (iv) $2p_y$
How many moles of methane are required to produce $11\ \text{g}$ $CO_{2(g)}$ after combustion? (Molar mass of $CO_{2}=44\ \text{g mol}^{-1}$)
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?
In the hydrogen spectrum, the shortest wavelength of the Brackett series is produced during the transition:
Light energy is redistributed in:
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:
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:
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:
If an inductor coil of self-inductance 2 H stores 25 J of magnetic energy, then the current I passing through it 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:
Chromatic aberration arises in thick lenses due to:
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:
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:
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:
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:
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: