41.

In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor, when the energy is stored equally between the electric and magnetic field is :

• $\frac{\mathrm{Q}}{2}$

• $\frac{\mathrm{Q}}{\sqrt{2}}$

• $\frac{\mathrm{Q}}{\sqrt{3}}$

• $\frac{\mathrm{Q}}{3}$

If v_g, v_x and v_m are the speeds of gamma rays, X rays and microwaves respectively in vacuum then :

• v_g > v_m > v_x

• v_g > v_x > v_m

• v_g = v_m = v_x

• none of these

n small metal drops of same size are charged to V volt each. If they coalesce to form a single large drop, then its potential will be:

• $\frac{\mathrm{V}}{\mathrm{n}}$

• Vn

• ${\mathrm{Vn}}^{\frac{1}{3}}$

• ${\mathrm{Vn}}^{\frac{2}{3}}$

A parallel plate air capacitor is charged and then isolated. When a dielectric material is inserted between the plates of the capacitor, then which of the following does not change?

• Electric field between the plates

• Potential difference across the plates

• Charge on the plates

• Energy stored in the capacitor

A spherical drop of mercury having a potential of 2.5 V is obtained as a result of merging 125 droplets. The potential of a constituent droplet would be

• 1.0 V

• 0.5 V

• 0.2 V

• 0.1 V

A person standing in front of a mirror finds his image larger than himself. This implies that the mirror is :

• convex

• parabolic

• plane

• concave

For a telescope, larger be the diameter of the objective lens:

• greater the resolving power

• smaller is the resolving power

• greater is the magnifying power

• smaller is the magnifying power

If the critical angle for total internal reflection from a medium to vacuum is 30°, the velocity of light in the medium is :

• 3 × 10⁸ m/s

• 1.5 × 10⁸ m/s

• 6 × 10⁸ m/s

• $\sqrt{3}$ × 10⁸ m/s

The deviation is maximum for which colour :

• Violet

• Red

• Blue

• Green

In single slit diffraction pattern

• central fringe has negligible width than others

• all fringes are of same width

• central fringe does not exist

• none of the above