NEET Physics MCQs

The ratio of resolving powers of an optical microscope for two wavelengths and ${\lambda _1} = 4000{A^ \circ }$ and ${\lambda _2} = 6000\,{A^ \circ }$ is

Two Polaroids ${P_1}{\rm{ \;and \;}}{P_2}$ are placed with their axis perpendicular to each other. Unpolarised light ${I_0}$ is incident on ${P_1}{\rm{.}}$ A third Polaroid ${P_3}$ is kept in between ${P_1}{\rm{\; and\; }}{P_2}$ such that its axis ,makes an angle ${45^ \circ }$ with that of ${P_1}{\rm{.}}$ The intensity of transmitted light through ${P_2}$ is

Young’s double slit experiment is first performed in air and then in a medium other than air. It is found that ${8^{th}}$ bright fringe in the medium lies where ${5^{th}}$ dark fringe lies in air. The refractive index of the medium is nearly.

The photoelectric threshold wavelength of silver is $3250 imes {10^{ - 10}}{\rm{ m}}{\rm{.}}$The velocity of the electron ejected from a silver surface by ultraviolet light of wavelength $2536 imes {10^{ - 10}}{\rm{ms}}$(Given $h = 4.14 imes {10^{ - 15}}{\rm{ eVs \;and \;}}c = 3 imes {10^8}{\rm{ m}}{{\rm{s}}^{ - 1}}$)

The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

In a common emitter transistor amplifier, the audio signal voltage across the collector is 3V. The resistance of collector is 3V. The resistance of collector is $3{\rm{ k}}\Omega \,{\rm{.}}$ If current gain is 100 and the base resistance is ${\rm{2 k}}\Omega \,,$ the voltage and power gain of the amplifier is

A spherical black body with a radius of $12\;{\rm{ cm}}$ radiates ${\rm{450\; Watt}}$ power at ${\rm{500\; K}}{\rm{.}}$If the radius were halved and the temperature doubled, the power radiated in watt would be

The two nearest harmonics of a tube closed at one end and open at other end are $220\,{\rm{Hz \;and \;260\, Hz}}{\rm{.}}$ What is the fundamental frequency of the system?

Two cars moving in opposite directions approach each other with speed of $22\,\,{\rm{m/s}}\;\,{\rm{and}}\;{\rm{16}}.{\rm{5}}\,\,{\rm{m/s}}$ respectively. The driver of the first car blows a horn having a frequency $400{\mkern 1mu} \,{\rm{Hz}}.$The frequency heard by the driver of the second car is [velocity of sound $340\;{\rm{ m/s}}$]