List of practice Questions

The recoil speed of a hydrogen atom after it emits a photon in going from $n = 5$, state to $n = 1$ state is
The real part of $( {1 - cos \, \theta + i \, sin \, \theta} )^{-1} $ is
The real values of $x$ and $y$ for which the following equality hold, are respectively $(x^{4}+2xi)-(3x^{2}+iy)=(3-5i)+(1+2iy)$
"The rate of loss of heat $-dQ/dt$ of the body is directly proportional to the temperature difference $\Delta T = (T_2 - T_1)$ of the body and surroundings". This statement is
The radius of the nuclues is proportional (if A is the atomic mass number)
The radius of $n^{th}$ orbit $r_n$ in terms of Bohr radius $(a_0)$ for a hydrogen atom is given by the relation
The radio waves of frequency $30\, MHz$ to $300 \,MHz$ belong to
The $r_+ / r_-$ ratio of ZnS is 0.402. Pick out the false statements of the following
The purpose of smelting an ore is
The pressure exerted by $5$ moles of a real gas in one litre vessel at $47^??$ is $(a = 3.592 \,atm\, L^2\, mol^{-2}$, $b = 0.0427\, L\, mol^{-1})$
The name hydrogen was given by
The length of a seconds pendulum is
The mobility of free electrons (charge= e, mass= m and relaxation time = $\tau$) in a metal is proportional to
The minimum and maximum distance of a satellite from the center of earth is 2R and 4R respectively. Its maximum speed is
The maximum amount of $BaSO_4$ precipitated on mixing $BaCl_2 (0.5 M)$ with $H_2SO_4$(1 M) will correspond to
The maximum amplitude of an amplitude modulated wave is found to be $15\, V$ while its minimum amplitude is found to be $3 \,V$. The modulation index is
The hydroxide of which of the following element is amphoteric?
The hydride ion, $H^-$, is a stronger base than the hydroxide ion, $OH^-$. Which one of the following reactions will occur if sodium hydride (NaH) is dissolved in water?
The hybridisation and geometry of $ B $ and $ N $ in $ [H_3B {
The hot wire instrument measures :
The human chromosome with the highest and least number of genes in them are respectively
The helium atom does not contain
The heat of transition is the heat evolved or absorbed when a substance is converted from
The heat of formation of water is 260 kJ. How much $H_2O$ is decomposed by 130 kJ of heat ?
The heat of neutralisation is maximum when