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A light of frequency 1.5 times the threshold frequency,is incident on photo-sensitive material. If the frequency is halved and intensity is doubled, the photoelectric current becomes....................
final friquency $ { 1.5 \over 2 } f_0 = 0.75 f_0 < f_0 $ therefore photoelectry current is zero
The work function of a metal is 1 eV. Light of wavelength $ 3000 A ^ \circ $ is incident on this metalsurface. The maximum velocity of emitted photoelection will be..................
$ { 1 \over 2 } mv^2 max = { hc \over \lambda } - \phi $ $ = ( {6.62 \times 10^{-34} \times 3.0 \times 10^8 \over 3.0 \times 10^{-7} \times 1.6 \times 10^{-19}} -1) eV $ $ = 3.1375 eV = 5.02 \times 10 h -19 J $ $ \therefore V_{max} = \sqrt { 2 \times 5.0 \times 2 \times 10^{-19} \over 9.1 \times 10^{-31 } }$ $ ( \therefore m = 9.1 \times 10^{-31} kg )$ $ = 1.05 \times 10^6 = 1 \times 10^6 ms^{-1} J$
The work function for tungsten and solidum are 4.5 eV and 2.3 eV respectively. If the threshold wavelength $ \lambda _0 $ for sodium is $ 5460 A ^ \circ $ the value of $ \lambda_0$ for tungsten is....................
$ \phi = hf _0 $ $ = { hc \over \lambda_0 } J = { hc \over \lambda_0 e } eV $ $ \therefore \lambda_0 \alpha {1 \over 0 } $ $ \therefore {\varphi_0( tungsten) \over \varphi _0 (sodium) }= { \varphi (tungsten) \over \varphi (sodium) } ={ 2.3 \over 4.5} $ $ \therefore \lambda_0 tungsten = { 2.3 \over 4.5 } \times 5460 A ^ \circ $ $ = 2790.6 = 2791 A ^ \circ $
In the Davissionand Germer's experiment the filament of electron gun is coated with.........
In the Davisson and Germer experiment, the filament of the electron gun is coated with barium oxide (BaO). This coating helps in the efficient emission of electrons when heated.
Suppose $ \Psi (x,y,z) $ represents a particle in three dimensional space, then probility of finding the particle in the unit volume at a given point x,y,z is .........
The probability of finding a particle at a given point in space is directly proportional to the square of the wave function's magnitude, $| \\Psi|^2$. This is because the probability density is given by $\\rho(x,y,z) = | \\Psi(x,y,z)|^2$. Therefore, the correct option is 'directly proportional to $ | \\Psi \\Psi ^ * | $'.
Select the correct statement from the following
In which of the following phenomena the photon picture is required?
Calculate the energy of a photon of radian wavelength $ 6000 A ^ \circ $ in eV.
$ E = hf = h { C \over \lambda } $ $ = { 6.62 \times 10^ {-34} \times 3.0 \times 10^8 } $ $ = 3.31 \times 10^ {-19 } J $ $ = { 3.31 \times 10^{-19 } \over 1.6 \times 10 ^ {-19 }} eV $ $ = 2.06 eV $
A 100 W bulb with 10% efficiency is placed at the centre of a sphere (hollow) of radius$ { 1 \over \sqrt {4 \pi} }$ Find the number of photons arriving on unit area ofthe surface in the unit time.
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The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.