Physics Modern Physics questions from NEET UG 2020.
In Bohrs model, the radius of nth orbit is proportional to
When a uranium isotope $U92235$ is bombarded with a neutron, it generates $\mathrm{Kr}3689$, three neutrons and:
An intrinsic semiconductor is converted into $n$-type extrinsic semiconductor by doping it with:-
Which of the following gate is called universal gate?
The total energy of an electron in the ${n}^{\text{th }}$ stationary orbit of the hydrogen atom can be obtained by
Out of the following which one is a forward biased diode?
For the logic circuit shown, the truth table is: 
The de-Broglie wavelength of an electron moving with kinetic energy of $144\mathrm{eV}$ is nearly
What happens to the mass number and atomic number of an element when it emits $\gamma$-radiation
The increase in the width of the depletion region in a p-n junction diode is due to:
The half life of radioactive sample undergoing $\alpha$-decay is $1.4\times {10}^{17}s.$ If the number of nuclei in the sample is $2.0\times {10}^{21},$ the activity of the sample is nearly:
Light of frequency $1.5$ times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?
The energy equivalent of $0.5g$ of a substance is:
An electron is accelerated from rest through a potential difference of $V$ volt. If the de Broglie wavelength of the electron is $1.227\times {10}^{–2} \mathrm{nm}$, the potential difference is:
The solids which have the negative temperature coefficient of resistance are:
For which one of the following, Bohr model is not valid?