NEET UG 2023 — Modern Physics

In hydrogen spectrum, the shortest wavelength in the Balmer series is$\lambda$. The shortest wavelength in the Brackett series is :

The minimum wavelength of $X$-rays produced by an electron accelerated through a potential difference of$V$ volts is proportional to:

The given circuit is equivalent to 

The wavelength of Lyman series of hydrogen atom appears in

A full wave rectifier circuit consists of two $p-n$ junction diodes, a centre-tapped transformer, capacitor and a load resistance. Which of these components remove the ac ripple from the rectified output?

For the following logic circuit, the truth table is: 

A p-type extrinsic semiconductor is obtained when Germanium is doped with

The half life of a radioactive substance is$20$minutes. In how much time, the activity of substance drops to $(\frac{1}{16})th$ of its initial value?

The maximum kinetic energy of the emitted photoelectrons in photoelectric effects is independent of:

The work functions of Caesium $(Cs)$, Potassium$(K)$ and Sodium $(Na)$ $2.14\mathrm{eV},2.30\mathrm{eV}\text{and}2.75\mathrm{eV}$ are respectively. If incident electromagnetic radiation has an incident energy of $2.20\mathrm{eV}$, which of these photosensitive surfaces may emit photoelectrons?

Given below are two statements: Statement$I$: Photovoltaic devices can convert optical radiation into electricity. Statement$II$: Zener diode is designed to operate under reverse bias in breakdown region. In the light of the above statements, choose the most appropriate answer from the options given below:

The radius of inner most orbit of hydrogen atom is $5.3\times {10}^{-11}m$. What is the radius of third allowed orbit of hydrogen atom?

The angular momentum of an electron moving in an orbit of hydrogen atom is $1.5\left(\frac{\mathrm{h}}{\pi}\right)$. The energy in the same orbit is nearly

The de Broglie wavelength associated with an electron, accelerated by a potential difference of $81 \mathrm{~V}$ is given by:

The ground state energy of hydrogen atom is $-13.6 \mathrm{eV}$. The energy needed to ionize hydrogen atom from its second excited state will be