List of practice Questions

The correct order of density of Be, Mg, Ca, Sr is:
Identify the reaction in which diborane is produced on an industrial scale:
Which of the following properties is not correct for silicones?
Match the following pollutant concentration limits in water with their effects:
A molecule has a T-shape. The total number of electron pairs in the valence shell of its central atom is:
The sum of bond order values of \( C_2 \) and \( O_2^{2-} \) is \( x \), which is equal to the sum of bond order values of \( a, b, \) and \( c \). What are \( a, b, \) and \( c \)?
At \( 27^\circ C \) kinetic energy of 4 g of \( H_2 \) is \( x \) J. What is the kinetic energy (in J) of 6.4 g of oxygen at \( 127^\circ C \)?
Which one of the following reactions is not feasible?
For which reaction \( \Delta H \neq \Delta U \)?
The ratio of the orders of the spacings of nuclear energy levels and atomic energy levels is:
The voltage gain and the current amplification factor of a transistor in common emitter configuration are \( 300 \) and \( 60 \) respectively. If the collector resistance is \( 5 k\Omega \), then the base resistance is:
The logic gate equivalent to the circuit shown in the figure is:
The logic gate equivalent
If the maximum and minimum amplitudes of a modulated wave are \( 25 \) V and \( 5 \) V respectively, then the modulation index is:
The radius of fourth orbit in \( He^+ \) ion is \( R_1 \) pm and radius of third orbit in \( Li^{2+} \) ion is \( R_2 \) pm. The value of \( (R_1 - R_2) \) in pm is:
The de Broglie wavelengths of two fast-moving particles \( X \), \( Y \) are \( 1 \) nm, \( 3 \) nm respectively. Mass of \( X \) is nine times the mass of \( Y \). The ratio of kinetic energies of \( X \), \( Y \) is:
The electronic configurations of four elements A, B, C, D are given below:
(A) 1s22s22p63s1
(B) 1s22s22p63s23p1
(C) 1s22s22p63s2
(D) 1s22s22p63s23p2
A long straight wire of circular cross-section of radius \( a \) is carrying a steady current. The current is distributed uniformly across the cross-section of the wire. The ratio of the magnetic fields at points \( 0.5a \) and \( 1.5a \) from the centre of the wire is:
Materials suitable for permanent magnets should have:
If a wheel with 24 metallic spokes each \( 40 \) cm long is rotated with a speed of \( 180 \) rev/min in a plane normal to the horizontal component of Earth's magnetic field, the emf induced between the axle and the rim of the wheel is \( E \). If the number of spokes is made \( 12 \) and the wheel is rotated with a speed of \( 90 \) rev/min in the same field, the induced emf is:
If a resistor of resistance \( 4 \Omega \), a capacitor of capacitive reactance \( 6 \Omega \) and an inductor of inductive reactance \( 9 \Omega \) are connected in series with an AC source, then the impedance of the circuit is:
The ratio of the magnitudes of the electric field and \( 10^8 \) times the magnetic field of a plane electromagnetic wave is:
If a proton and an alpha particle are accelerated through the same potential difference, then the ratio of their de Broglie wavelengths is:
Of the following, Bohr's atomic model is applicable to:
In Young's double slit experiment, the distance between the slits is \( 0.2 \) cm, the distance between the screen and the slits is \( 1 \) m. If the wavelength of light used in the experiment is \( 5000 \) Å, then the distance between two consecutive dark fringes on the screen is:
The capacitance of a spherical capacitor is \( 100 \) pF. If the spacing between the two spheres is \( 1 \) cm, then the radius of the inner sphere of the capacitor is: