Wave Optics — Physics STD 12 Science — Question

A charged particle oscillates about its mean equilibrium position with a frequency of 10⁹Hz. The frequency of electromagnetic waves produced by the oscillator is:

In an electromagnetic wave.

A set of atoms in an excited state decay.

When a proton is accelerated with 1 volt potential difference, then its kinetic energy is

(a)

(b) 1840 eV

(c) 1 eV

(d) 1840 c2 eV

The following diagram indicates the energy levels of a certain atom when the system moves from 2E level to E, a photon of wavelength λ  is emitted. The wavelength of photon produced during its transition from   level to E is

(a) λ/3

(b) 3 λ/4

(c) 4 λ/3

(d) 3 λ

The magnetic field at a distance r from a long wire carrying current i is 0.4 Tesla. The magnetic field at a distance 2r is

(a) 0.2 Tesla

(b) 0.8 Tesla

(c) 0.1 Tesla

(d) 1.6 Tesla

Which of the following series of hydrogen spectrum is in visible range?

Two identical p-ri junctions may be connected in series with a battery in three ways (figure). The potential difference across the two p-n. junctions are equal in:

The electric potential at a point on the equatorial line of an electric dipole is:

Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field by both coils, if the same current is  flown

(a) 1:

(b) 1 : 2

(c) 2 : 1

(d)