List of practice Questions

If \(n\), \(e\), \(\tau\), and \(m\) represent the concentration, the charge, the relaxation time, and the mass of an electron in a metal, then the resistance of a wire made of the metal of length \(l\) and cross-sectional area \(A\) is:

In a potentiometer experiment, the balancing length with a cell is \(240~\text{cm}\). On shunting the cell with \(2~\Omega\), the balancing length becomes \(120~\text{cm}\). The internal resistance of the cell is

To generate the high magnetic fields, the synchrotron uses

If the magnetic field is along the positive y-axis and the electron is moving along the positive x-axis, the direction of force on the electron is

A bar magnet of length \(0.1~\text{m}\) and magnetic moment of \(5~\text{Am}^2\) is placed in a uniform magnetic field of intensity \(0.4~\text{T}\), with its axis making an angle of \(60^\circ\) with the field. The torque on the magnet is

Changing magnetic fields can set up current loops in nearby metal bodies. They dissipate electrical energy as heat. Such currents are called

A resistor of \(50~\Omega\), an inductor and a capacitor are connected in series to an AC source of peak voltage \(200\sqrt{2}~\text{V}\).
When the capacitor alone is removed, current lags voltage by \(37^\circ\).
When the inductor alone is removed, current leads voltage by \(37^\circ\).
The power dissipated in the LCR circuit is:

The efficiency of a bulb of \(1000~\text{W}\) is \(6%\). The peak value of the magnetic field produced by the electromagnetic radiation from the bulb at a distance of \(1~\text{m}\) is: \[ \left( \frac{1}{4\pi \varepsilon_0} = 9 \times 10^9~\text{Nm}^2\text{C}^{-2} \right) \]

Two photons each of energy \(2~\text{eV}\) incident simultaneously on a photosensitive material of work function \(3~\text{eV}\). The maximum kinetic energy of the emitted photoelectrons is

An electron in the ground state of hydrogen atom absorbs \(10.2~\text{eV}\) energy. The orbital angular momentum of the electron increases by

If the speed of light was half the present value, the energy released in a nuclear reaction decreases by

In the given logic circuit, if A and B are the inputs, then P and Q are respectively
\

An oscillator is an amplifier with

A message signal of frequency \(20~\text{kHz}\) and peak voltage \(20~\text{V}\) is used to modulate a carrier of peak voltage \(100~\text{V}\). The modulation index is

The radius of H atom in its ground state is \(x~\text{pm}\). What is the ratio of radii in ground and \(n = 2\) states of He\(^+\)?

The total number of electrons with magnetic quantum number \(m_l = 0\) in Fe\(^{3+}\) and Cr\(^+\) is respectively

How many of the following are neutral oxides?
CO, NO, Na\(_2\)O, N\(_2\)O, Cl\(_2\)O\(_7\), Al\(_2\)O\(_3\), As\(_2\)O\(_3\)

The metal having low melting point is

Intramolecular hydrogen bonding is found in

In the given figure, AB=AD. ∠ACB=95°+ ∠BAC and ∠BAD=150°. Find ∠ACB.

The isotopes of hydrogen are H, D and T. What is the approximate ratio of rate of diffusion of H\(_2\), D\(_2\), and T\(_2\)?

A gaseous mixture containing H\(_2\), He, and O\(_2\) exerts a pressure of 1 bar. The weight percentage of H\(_2\) and He is 20 and 16 respectively. What is the ratio of partial pressures of O\(_2\), He and H\(_2\)?

If the standard Gibbs energy, enthalpy and entropy changes \(\Delta G^\circ\), \(\Delta H^\circ\) and \(\Delta S^\circ\) for a reaction are \(-34.44~\text{kJ mol}^{-1}\), \(-6.44~\text{kJ mol}^{-1}\), and \(80~\text{J K}^{-1} \text{mol}^{-1}\) respectively, the temperature of the reaction (in \(^\circ\text{C}\)) is

If the mean bond dissociation energies of C–C and C–H are 80 and 90 kJ mol\(^{-1}\) respectively, the standard enthalpy of atomization of n-butane(g) (in kJ mol\(^{-1}\)) is

At T(K), the solubility products (K\(_{sp}\)) of AgCl, AgBr and AgI are \(1.8 \times 10^{-10}\), \(5 \times 10^{-13}\) and \(8.3 \times 10^{-17}\) respectively. A 1L solution contains \(10^{-5}\) moles each of NaCl, NaBr and NaI. This solution is titrated with \(10^{-6}\) M AgNO\(_3\) until all halides (Cl\(^{-}\), Br\(^{-}\), I\(^{-}\)) are precipitated as silver salts.
The order of precipitation of these respectively is: