The energy stored in a capacitor of capacitance C having a charge Q under a potential V is

• $\frac{1}{2}{\mathrm{Q}}^2\mathrm{V}$

• $\frac{1}{2} {\mathrm{C}}^2\mathrm{V}$

• $\frac{1}{2} \frac{{\mathrm{Q}}^2}{\mathrm{V}}$

• $\frac{1}{2} \mathrm{QV}$

The electrostatic force between two point charges is directly proportional to the

• sum of the charges

• distance between the charges

• product of the charges

• permittivity of the medium

53.

The time period of revolution of a charge q₁ and of mass m moving in a circular path of radius r due to Coulomb force of attraction with another charge q₂ at its centre is

• $\sqrt{\frac{16{\mathrm{\pi \epsilon }}_0{\mathrm{mr}}^3}{{\mathrm{q}}_1{\mathrm{q}}_2}}$

• $\sqrt{\frac{8{\mathrm{\pi }}^2{\mathrm{\epsilon }}_0{\mathrm{mr}}^3}{{\mathrm{q}}_1{\mathrm{q}}_2}}$

• $\sqrt{\frac{{\mathrm{\epsilon }}_0{\mathrm{mr}}^3}{16 {\mathrm{q}}_1{\mathrm{q}}_2}}$

• $\sqrt{\frac{16{\mathrm{\pi }}^3{\mathrm{\epsilon }}_0{\mathrm{mr}}^3}{{\mathrm{q}}_1{\mathrm{q}}_2}}$

A point charge of 2 C experiences a constant force of 1000 N when moved between two points separated by a distance of 2 cm in a uniform electric field. The potential difference between the two points is

• 12 V

• 8 V

• 10 V

• 16 V

In the network shown below, if potential across XY is 4 V, then the input potential across AB is

• 16 V

• 20 V

• 8 V

• 12 V

If the ammeter A shows a zero reading in the circuit shown below, the value of resistance R is

• 500 Ω

• 125 Ω

• 100 Ω

• 41.5 Ω

The apparent flattening of the sun at sunset and sunrise is due to

• refraction

• diffraction

• total internal reflection

• interference

The polarising angle for a medium is found to be 60°. The critical angle of the medium is

• ${\sin }^{-1} \left(\frac{1}{2}\right)$

• ${\sin }^{-1} \left(\frac{\sqrt{3}}{2}\right)$

• ${\sin }^{-1} \left(\frac{1}{\sqrt{3}}\right)$

• ${\sin }^{-1} \left(\frac{1}{4}\right)$

Identify the mismatch in the following

• Myopia  —  Concave lens

• For rear view  —  Concave mirror

• Hypermetropia  —  Convex lens

• Astigmatism  —  Cylindrical lens

In Young's double slit experiment, to increase the fringe width

• the wavelength of the source is increased

• the source is moved towards the slit

• the source is moved away from the slit

• the slit separation is increased