List of practice Questions

Diborane on hydrolysis gives a compound X. The correct statements about X are I. It is a tribasic acid II. It is a weak monobasic acid III. It has a layer structure IV. It is highly soluble in water
If the sum of bond orders of O$_2$ and O$_2^-$ is x, then bond order of O$_2^+$ will be
Identify the molecule / ion in which the ratio of $\sigma$ to $\pi$ bonds is 3:2
At 298K, a flask 'A' of unknown volume (V) contains oxygen at 5 atm. Another flask 'B' of volume 2L contains helium at 3 atm. Two flasks are connected together by a small tube of zero volume. After the two gases are completely mixed, if the resulting mixture is found to have the mole fraction of oxygen as 0.2, the volume of flask 'A' (in L) is (Assume oxygen and helium as ideal gases)
In which of the following, oxidation state of nitrogen is lowest?
Which of the following processes are reversible? I. Vaporization of a liquid at its boiling point. II. Expansion of gas into vacuum. III. Transformation of a solid substance into liquid at its melting point. IV. Neutralization of an acid by a base.
At T(K) in a saturated solution of MgCO$_3$ and Ag$_2$CO$_3$, if the concentration of Mg$^{2+}$ ion is $3.2\times10^{-5}$ M, then the concentration of Ag$^+$ ion in the solution will be [Given: $K_{sp}(MgCO_3)=1.6\times10^{-6}$ and $K_{sp}(Ag_2CO_3)=8.0\times10^{-12}$ at T(K)]
The layer of the atmosphere which efficiently reflects high frequency waves particularly at night is
In the atomic spectrum of hydrogen, the wavelengths of the spectral lines corresponding to electronic transitions (i) n = 4 to n = 2 and (ii) n = 3 to n = 1 are $\lambda_1$ and $\lambda_2$ \AA{}respectively. The value of $(\lambda_1 - \lambda_2)$ (in cm) is ($R_H$ = Rydberg constant)
Work functions of four metals M$_1$, M$_2$, M$_3$ and M$_4$ are 4.8, 4.3, 4.75 and 3.75 eV respectively. The metals which do not show photoelectric effect when light of wavelength 310 nm falls on the metals are
In second period of the modern periodic table, two elements X and Y have higher first ionization enthalpy values than the preceding and succeeding elements. X and Y are respectively
Consider the following pairs of elements and identify the pairs of elements which have nearly same atomic radius. I. Y, La II. Zr, Hf III. Mo, W IV. Cr, Mo
When photons incident on a photosensitive material of work function 1.5 eV, the maximum velocity of the emitted photoelectrons is $8\times10^5$ ms$^{-1}$. The stopping potential of the photoelectrons is (Mass of the electron $= 9\times10^{-31}$ kg and charge of the electron $= 1.6\times10^{-19}$ C)
The potential energy of an electron in an orbit of hydrogen atom is -6.8 eV. The de Broglie wavelength of the electron in this orbit is ($r_0$ is Bohr radius)
If a radioactive substance decays 10% in every 16 hours, then the percentage of the radioactive substance that remains after 2 days is
If a nucleus P converts into a nucleus Q by the decay of one alpha particle and two $\beta^-$ particles, then the nuclei P and Q are
The graph between the input voltage ($V_i$) and the output voltage ($V_o$) of a transistor connected in common emitter configuration is shown in the figure. The active, saturation and cutoff regions of the transistor are respectively
Which of the following logic gates is a universal gate?
An alpha particle moving with certain speed towards east enters a uniform magnetic field directed vertically up. The alpha particle will then move in
The ratios of the voltage sensitivities, resistances and areas of the coils of two moving coil galvanometers A and B are 4:3, 3:4 and 1:2 respectively. If the number of turns of the coil of galvanometer A is 200, then the number of turns of the coil of galvanometer B is (All other quantities remain same in both the cases)
A solenoid of 1000 turns per metre has a core of material with relative permeability 400. The windings of the solenoid are insulated from the core and a current of 2 A is passed through the solenoid. Then the value of the magnetic intensity inside the solenoid is
An emf of 2.8 mV is induced in a rectangular loop of area 150 cm$^2$ when the current in the loop changes from 3 A to 8 A in a time of 0.2 s. Then the self-inductance of the loop is
A capacitor and a resistor of resistance $100\sqrt{3}\Omega$ are connected in series to an ac source of voltage $100\sin(200t)$ V, where 't' is time in second. If the phase difference between the voltage and the current in the circuit is 30$^\circ$, then the capacitance of the capacitor is
The amplitude of the electric field associated with a light beam of intensity $\frac{15}{\pi}$ Wm$^{-2}$ is
A convex lens of radii of curvature 6 cm and 12 cm is immersed in a liquid of refractive index 1.3. If the refractive index of the material of the lens is 1.5, then the focal length of the lens when immersed in the liquid is