List of practice Questions

Match the following pollutant concentration limits in water with their effects:
Identify the reaction in which diborane is produced on an industrial scale:
A molecule has a T-shape. The total number of electron pairs in the valence shell of its central atom is:
At \( 298 \) K, \( \Delta U^\circ \) and \( \Delta S^\circ \) for the following reaction are \( -10.5 \) kJ and \( +44.1 \) J\( K^{-1} \); \( 2X(g) + Y(g) \longrightarrow 2Z(g) \). What is \( \Delta G^\circ \) (in kJ) for this reaction? (\( R = 8.314 \) J\( K^{-1} \)mol\(^{-1} \))
For which reaction \( \Delta H \neq \Delta U \)?
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 \( 127^\circ C \)?
At \( T \)(K), hydrogen and oxygen gases are mixed in the ratio of \( 1:2 \) by mass in a closed vessel of volume \( V \) litres. If the total pressure of the gaseous mixture is \( p \) atm, the partial pressure of oxygen (in atm) is:
Which one of the following reactions is not feasible?
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 \( c \)?
The electronic configurations of four elements A, B, C, D are given below:
(A) 1s22s22p63s1
(B) 1s22s22p63s23p1
(C) 1s22s22p63s2
(D) 1s22s22p63s23p2
The logic gate equivalent to the circuit shown in the figure is:
The logic gate equivalent
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:
If the maximum and minimum amplitudes of a modulated wave are \( 25 \) V and \( 5 \) V respectively, then the modulation index 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 ratio of the orders of the spacings of nuclear energy levels and atomic energy levels 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:
Materials suitable for permanent magnets should have:
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:
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:
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:
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:
The ratio of the magnitudes of the electric field and \( 10^8 \) times the magnetic field of a plane electromagnetic wave is:
A wire of resistance \( R \) is bent in the form of a circular loop. Two points on the circle separated by a quarter circumference are connected to a battery of emf \( E \) and negligible internal resistance. The heat generated in the wire per second is:
When a wire is connected in the left gap of a metre bridge, the balancing point is at \( 40 \) cm from the left end of the bridge wire. If the wire in the left gap is stretched so that its length is doubled and again connected in the same gap, then the balancing point from the left end of the bridge wire is: