List of practice Questions

Assertion (A) : When a convex lens made of glass is immersed in water, its converging power increases. Reason (R) : The focal length of a lens depends only on the radii of curvature of its two faces.

Assertion (A) : The conductivity of an n-type semiconductor is higher than that of a p-type semiconductor at a given temperature. Reason (R) : The electrons being in the conduction band in n-type semiconductor are more mobile than the holes in the valence band in p-type semiconductor.

An electric dipole consists of two point charges \(+1\,\mu\text{C}\) and \(-1\,\mu\text{C}\), held 10 cm apart. It is subjected to a uniform electric field of \(100\,\text{N/C}\). Calculate the amount of work done in turning the dipole from its position of stable equilibrium to the position of unstable equilibrium, in the field.

The ratio of amplitude of electric field to the amplitude of the magnetic field associated with an electromagnetic wave propagating in glass \((n=1.5)\) is :

While studying photoelectric emission from a given surface, the wavelength of the incident radiation is changed from \(600\,\text{nm}\) to \(400\,\text{nm}\), keeping the intensity of radiation the same. Then :

Radiation of wavelength \(331\ \text{nm}\) irradiates the following metals :

Which of the following statements is correct ?

The kinetic energy of a charged particle is increased to four times of its initial value. The de Broglie wavelength associated with the particle will :

Paschen series in spectrum of hydrogen atom lies in :

In a reversed-biased p-n junction diode, the applied voltage mostly drops across :

Two wires of same length and same area of cross-section but made of different materials of resistivities \( \rho_1 \) and \( \rho_2 \) are connected in series. The equivalent resistivity of the combination is :

Two particles of masses \(m_1\) and \(m_2\) having charges \(q_1\) and \(q_2\) respectively are projected with the same velocity in a region of uniform magnetic field \(\vec{B}\) pointing vertically upward. If they describe circular paths as shown in the figure, one may conclude that :

An electron moves around the nucleus in a circular orbit of radius \(r\) and makes \(n\) revolutions per second. The value of equivalent current in the orbit is :

The dimensions of the rate of change of magnetic flux are :

Two identical conductors 1 and 2 are placed on two frictionless conducting rails R and S in a uniform magnetic field directed vertically downward into the plane of the page. If conductor 1 is moved with a constant velocity in the direction as shown in figure, the force on conductor 2 will be along :

An ac voltage is given as \(v = 14\sin(314t)\,\text{V\). The average and the effective value of the voltage (in V) over a cycle are respectively :}

“India has given priority to non-traditional security in the last two decades.” Analyse the statement with examples.

Describe any three major developments witnessed by Punjab that led to dissatisfaction and violence.

Describe any three measures that can be taken by the Union government to address the regional movements and demands.

State any four major political happenings of the decade of the nineties which had a widespread impact.

Describe any four issues on which a broad agreement has emerged among most of the political parties in India.

Write the main objective of the United Nations.

Which organ of the United Nations has five permanent members?

Name any one international Non-Governmental Organization (NGO) that campaigns for the protection of Human Rights.

Why is 'Shock Therapy' considered a painful process of transition from an authoritarian socialist system to a democratic capitalist system? Explain any three reasons.

Explain any four reasons for the disintegration of the Soviet Union.