Wave Optics Tes...

In a single slit diffraction experiment first minimum for red light (660 nm) coincides with first maximum of some other wavelength λ\' . The value of λ\' is

The ratio of intensities of consecutive maxima in the diffraction pattern due to a single slit is

Light is incident normally on a diffraction grating through which the first order diffraction is seen at 32°. The second order diffraction will be seen at

White light may be considered to be a mixture of waves with λ ranging between 3900 Å and 7800 Å. An oil film of thickness 10,000 Å is examined normally by reflected light. If µ = 1.4 , then the film appears bright for

Among the two interfering monochromatic sources A and B; A is ahead of B in phase by 66°. If the observation be taken from point P, such that PB – PA = λ/4. Then the phase difference between the waves from A and B reaching P is

A parallel plate capacitor of plate separation 2 mm is connected in an electric circuit having source voltage 400 V. If the plate area is 60 cm², then the value of displacement current for 10^–6s will be

A long straight wire of resistance R, radius a and length l carries a constant current I. The Pointing vector for the wire will be

In an electromagnetic wave, the amplitude of electric field is 1 V/m. The frequency of wave is 5 × 10¹⁴ Hz. The wave is propagating along z-axis. The average energy density of electric field, in Joule/m³, will be

A laser beam can be focussed on an area equal to the square of its wavelength. A He – Ne laser radiates energy at the rate of 1mW and its wavelength is 632.8 nm. The intensity of focussed beam will be

A lamp emits monochromatic green light uniformly in all directions. The lamp is 3% efficient in converting electrical power to electromagnetic waves and consumes 100W of power. The amplitude of the electric field associated with the electromagnetic radiation at a distance of 10m from the lamp will be