The spectral series of the hydrogen atom that lies in the visible region of the electromagnetic spectrum

• Paschen

• Balmer

• Lyman

• Brackett

The angle of minimum deviation for an incident light ray on an equilateral prism is equal to its refracting angle. The refractive index of its material is

• $\frac{1}{\sqrt{2}}$

• $\sqrt{3}$

• $\frac{\sqrt{3}}{2}$

• $\frac{3}{2}$

In the following combinations of logic gates, the outputs of A, B and C are respectively

• 0, 1, 1

• 0, 1, 0

• 1, 1, 0

• 1, 0, 1

The phenomena in which proton flips is

• nuclear magnetic resonance

• lasers

• radioactivity

• nuclear fusion

According to the quark model, it is possible to build all the hadrons using

• 2 quarks and 3 antiquarks

• 3 quarks and 2 antiquarks

• 3 quarks and 3 antiquarks

• 2 quarks and 2 antiquarks

56.

A parallel beam of light is incident on a converging lens parallel to its principal axis. As one moves away from the lens on the other side of the principal axis, the intensity of light

• first decreases and then increases

• continuously increases

• continuously decreases

• first increases and then decreases

Continuous emission spectrum is produced by

• incandescent electric lamp

• mercury vapour lamp

• sodium vapour lamp

• polyatomic substances

A ray of light is incident on a plane mirror at an angle of 60°. The angle of deviation produced by the mirror is

• 120°

• 30°

• 60°

• 90°

Young's double slit experiment gives interference fringes of width 0.3 mm. A thin glass plate made of material of refractive index 1.5 is kept in the path oflight from one of the slits, then the fringe width becomes

• zero

• 0.3 mm

• 0.45 mm

• 0.15 mm

Hydrogen atom from excited state comes to the ground stage by emitting a photon of wavelength λ. If R is the Rydberg constant, the principal quantum number n of the excited state

• $\sqrt{\frac{\mathrm{\lambda R}}{\mathrm{\lambda R} - 1}}$

• $\sqrt{\frac{\mathrm{\lambda }}{\mathrm{\lambda R} - 1}}$

• $\sqrt{\frac{{\mathrm{\lambda R}}^2}{\mathrm{\lambda R} - 1}}$

• $\sqrt{\frac{\mathrm{\lambda R}}{\mathrm{\lambda } - 1}}$