List of practice Questions

The valency shell of element A contains 3 electrons while the valency shell of element B contains 6 electrons. If A combines with B, the probable formula of the compound formed will be:
The enthalpy of sublimation of aluminium is \(330\,\text{kJ mol}^{-1}\). Its I\(^\text{st}\), II\(^\text{nd}\) and III\(^\text{rd}\) ionization enthalpies are 580, 1820 and \(2740\,\text{kJ mol}^{-1}\) respectively. How much heat must be supplied in kJ to convert 13.5 g of aluminium into Al\(^{3+}\) ions and electrons at 298 K?
Which one of the following pairs is isostructural (i.e., having the same shape and hybridization)?
N\(_2\) and O\(_2\) are converted into mono anions N\(_2^-\) and O\(_2^-\) respectively. Which of the following statements is wrong?
If the enthalpy of vaporization of water is \(18.6\,\text{kJ mol}^{-1}\), the entropy of its vaporization will be:
The heats of neutralisation of CH\(_3\)COOH, HCOOH, HCN and H\(_2\)S are \(-13.2, -13.4, -2.9\) and \(-3.8\) kcal per equivalent respectively. Arrange the acids in increasing order of acidic strength.
A nucleus of uranium decays at rest into nuclei of thorium and helium. Then:
Let binding energy per nucleon of nucleus be denoted by \(E_{bn}\) and radius of nucleus be denoted as \(r\). If mass number of nuclei A and B are 64 and 125 respectively then:
For a CE transistor amplifier, the audio signal voltage across the collector resistance of \(2.0\,\text{k}\Omega\) is \(2.0\,\text{V}\). Suppose the current amplification factor of the transistor is 100. What should be the value of \(R_B\) in series with \(V_{BB}\) supply of \(2.0\,\text{V}\) if the base current has to be 10 times the signal current?
The formation of CO and CO\(_2\) illustrates the law of:
The wave number of the limiting line in Lyman series of hydrogen is \(109678\,\text{cm}^{-1}\). The wave number of the limiting line in Balmer series of He\(^+\) would be:
If hydrogen atom, an electron jumps from bigger orbit to smaller orbit so that radius of smaller orbit is one-fourth of radius of bigger orbit. If speed of electron in bigger orbit was \(v\), then speed in smaller orbit is:
The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and the eye piece is found to be 20 cm. The focal length of lenses are:
The angular size of the central maxima due to a single slit diffraction (a = slit width) is:
The threshold wavelength of tungsten is \(2300\,\text{\AA}\). If ultraviolet light of wavelength \(1800\,\text{\AA}\) is incident on it, then the maximum kinetic energy of photoelectrons would be about:
A narrow beam of protons and deuterons, each having the same momentum, enters a region of uniform magnetic field directed perpendicular to their direction of momentum. The ratio of the radii of the circular paths described by them is:
The susceptibility of a magnetism at 300 K is \(1.2 \times 10^{-5}\). The temperature at which the susceptibility increases to \(1.8 \times 10^{-5}\) is:
A coil of 10 turns and resistance \(20\,\Omega\) is connected in series with a battery of resistance \(30\,\Omega\). The coil is placed with its plane perpendicular to a uniform magnetic field of induction \(10^{-2}\,\text{T}\). If it is now turned through an angle of \(60^\circ\) about an axis in its plane, the charge induced in the coil is (Area of coil \(=10^{-2}\,\text{m}^2\)):
Voltage and current in an AC circuit are given by \(V = 50\sin(50t)\,\text{V}\) and \(i = 50\sin(50t + \frac{\pi}{3})\,\text{mA}\). The power dissipated in the circuit is:
Resolving power of a telescope will be more, if the diameter of the objective is:
Two point dipoles \(p\hat{k}\) and \(\frac{p}{2}\hat{k}\) are located at \((0,0,0)\) and \((1\,\text{m},0,2\,\text{m})\) respectively. The resultant electric field due to the two dipoles at the point \((1\,\text{m},0,0)\) is:
Electric field in the region is given by \( \vec{E} = \left(\dfrac{M}{x^3}\right)\hat{i}\). The correct expression for the potential in the region is [assume potential at infinity is zero]:
Two coaxial non-conducting cylinders of radius \(a\) and \(b\) are separated by a material of conductivity \(\sigma\) and a constant potential difference \(V\) is maintained between them by a battery. The current per unit length flowing from one cylinder to the other is:
In the kinetic theory of gases, which of these statements is/are true? (i) The pressure of a gas is proportional to the mean speed of the molecules. (ii) The root mean square speed of the molecules is proportional to the pressure. (iii) The rate of diffusion is proportional to the mean speed of molecules. (iv) The mean translational kinetic energy of a gas is proportional to its kelvin temperature.
Two balloons are filled with pure gases and other with air respectively. If the pressure and temperature of these balloons are same, then the number of molecules per unit volume is: