List of practice Questions

The quantity of electricity required to produce 18 g of Al from molten Al\(_2\)O\(_3\) is (Atomic mass of Al = 27):
The value of \( K_c \) for the equilibrium reaction \[ 2 {NO}_2(g) \rightleftharpoons {N}_2{O}_4(g) \] is \(2 \times 10^{-40} \, {mol}^{-1} \, {dm}^3\) at 298 K. If the equilibrium concentration of \({NO}_2\) is \(2 \times 10^{-2}\) M, the concentration of \({N}_2{O}_4\) is:
In a process, 600 J of heat is absorbed by a system and 375 J of work is done by the system. The change in internal energy of the process is:
Which of the following is true for a reaction that is spontaneous only at high temperature?
Which of the following is used as anode in mercury cell?
The valence electron MO configuration of \( {C}_2 \) (atomic number of C = 6) molecule is:
The hybridization involved in the metal atom of \([CrF_6]^{3-}\) is:
The decreasing order of first ionization enthalpy of the following elements is:
Which of the following statements is incorrect about Bohr's model of the atom?
The volume of ethanol required to prepare 3 L of 0.25 M aqueous solution is (density of ethanol = 0.36 kg L\(^{-1}\), molar mass = 60 g mol\(^{-1}\)):
The molarity of sodium hydroxide in the solution prepared by dissolving 6 g in 600 mL of water is (molar mass of NaOH = 40 g mol\(^{-1}\)):
The current flowing from p to n side in a pn junction diode irrespective of biasing is termed:
In the electron emission process, \( _{Z}^{A}X \rightarrow _{Z+1}^{A}Y + e^{-} + \bar{\nu} \), the particle \( q \) emitted along with the electron is:
In a radioactive decay, the fraction of the number of atoms left undecayed after time \( t \) is:
The constancy of the binding energy per nucleon in medium-sized nuclei is due to:
For a given radioactive material of mean life \(\tau\) and half-life \(t_{1/2}\), the relationship between \(t_{1/2}\) and \(\tau\) is:
The wavelength of the de Broglie wave (in meter) associated with a particle of mass \(m\) moving with \(\frac{1}{10}\) of the velocity of light is (h = Planck's constant, c = velocity of light):

A parallel beam of light is incident from air at an angle \(\alpha\) on the side PQ of a right-angled triangular prism of refractive index \(\mu = \sqrt{2} \approx 1.414\). The beam of light undergoes total internal reflection in the prism at the face PR when \(\alpha\) has a minimum value of 45\(^{\circ}\). 
The angle \(\theta\) of the prism is: 

The oscillating magnetic field in a plane electromagnetic wave is given by \(B_y = (8 \times 10^{-6}) \sin[2 \pi \times 10^{11} t + 200 \pi x] \) tesla. Then the wavelength of the electromagnetic wave (in cm) is:
An electric appliance draws 3A current from a 200 V, 50 Hz power supply. The amplitude of the supply voltage is nearly:
When an \( \alpha \) particle and a proton are projected into a perpendicular uniform magnetic field, they describe circular paths of the same radius. The ratio of their respective velocities is:

The y-intercept of the graph between the terminal voltage \(V\) with load resistance \(R\) along \(y\) and \(x\) – axis, respectively, of a cell with internal resistance \(r\), as shown, is: 

Magnitude of drift velocity per unit electric field is known as:
A spherical metal shell \( A \) of radius \( R_A \) and a solid metal sphere \( B \) of radius \( R_B \) (\( R_B<R_A \)) are kept far apart and each is given charge \( +Q \). If they are connected by a thin metal wire and \( Q_A \) and \( Q_B \) are the charge on \( A \) and \( B \), respectively, then:
The electric field due to an infinitely long thin wire with linear charge density \( \lambda \) at a radial distance \( r \) is proportional to: