Modern Physics — JEE Advanced PYQs

Paragraph for Questions 11 and 12

The mass of a nucleus ${}_Z^{A}X$ is less than the sum of the masses of ( $A-Z$ ) number of neutrons and $Z$ number of protons in the nucleus. The energy equivalent to the corresponding mass difference is known as the binding energy of …

Paragraph for Questions 11 and 12

The mass of a nucleus ${}_Z^{A}X$ is less than the sum of the masses of ( $A-Z$ ) number of neutrons and $Z$ number of protons in the nucleus. The energy equivalent to the corresponding mass difference is known as the binding energy of …

Match List I of the nuclear processes with List II containing parent nucleus and one of the end products of each process and then select the correct answer using the codes given below the lists :
| R. | …

A proton is fired from very far away towards a nucleus with charge $Q=120e$, where $e$ is the electronic charge. It makes a closest approach of 10 fm to the nucleus. The de Broglie wavelength (in units of fm) of the proton at its start is: (take the proton mass, …

The $\beta$-decay process, discovered around 1900, is basically the decay of a neutron $(n)$. In the laboratory, a proton $(p)$ and an electron $\left(e^{-}\right)$are observed as the decay products of the neutron. Therefore, considering the decay of a neutron as a two-bo …

The $\beta$-decay process, discovered around 1900, is basically the decay of a neutron $(n)$. In the laboratory, a proton $(p)$ and an electron $\left(e^{-}\right)$are observed as the decay products of the neutron. Therefore, considering the decay of a neutron as a two-bo …

The wavelength of the first spectral line in the Balmer series of hydrogen atom is $6561\mathring{A}$. The wavelength of the second spectral line in the Balmer series of singly-ionized helium atom is

The activity of a freshly prepared radioactive sample is $10^{10}$ disintegrations per second, whose mean life is $10^9\mathrm{s}$. The mass of an atom of this radioisotope is $10^{-25}\mathrm{kg}$. The mass (in mg) of the radioactive sample is

A silver sphere of radius 1 cm and work function 4.7 eV is suspended from an insulating thread in free-space. It is under continuous illumination of 200 nm wavelength light. As photoelectrons are emitted, the sphere gets charged and acquires a potential. The maximum number of pho …

An $\alpha$-particle and a proton are accelerated from rest by a potential difference of 100V. After this, their de Broglie wavelengths are ${\lambda }_{\alpha }$ and ${\lambda }_p$ respectively. The ratio $\frac{{\lambda }_p}{{\lambda }_{\alpha }}$, to the nearest integer, is

To determine the half life of a radioactive element, a student plots a graph of $\ell n\left|\frac{\mathrm{dN}(\mathrm{t})}{\mathrm{dt}}\right|$ versus $t$. Here $\frac{dN(t)}{dt}$ is the rate of radioactive decay at time $t$. If the number of radioactive nuclei of this element …

The key feature of Bohr's theory of spectrum of hydrogen atom is the quantization of angular momentum when an electron is revolving around a proton. We will extend this to a general rotational motion to find quantized rotational energy of a diatomic molecule assuming it to be rig …

The key feature of Bohr's theory of spectrum of hydrogen atom is the quantization of angular momentum when an electron is revolving around a proton. We will extend this to a general rotational motion to find quantized rotational energy of a diatomic molecule assuming it to be rig …

The key feature of Bohr's theory of spectrum of hydrogen atom is the quantization of angular momentum when an electron is revolving around a proton. We will extend this to a general rotational motion to find quantized rotational energy of a diatomic molecule assuming it to be rig …

Photoelectric effect experiments are performed using three different metal plates $\mathrm{p},\mathrm{q}$ and r having work functions ${\varphi }_p=2.0\mathrm{eV},{\varphi }_q=2.5\mathrm{eV}$ and ${\varphi }_r=3.0\mathrm{eV}$, respectively. A light beam containing wavelengths of …

Scientists are working hard to develop nuclear fusion reactor. Nuclei of heavy hydrogen, ${}_1^2\mathrm{H}$, known as deuteron and denoted by D , can be thought of as a candidate for fusion reactor. The D-D reaction is …

Scientists are working hard to develop nuclear fusion reactor. Nuclei of heavy hydrogen, ${}_1^2\mathrm{H}$, known as deuteron and denoted by D , can be thought of as a candidate for fusion reactor. The D-D reaction is …

When a particle is restricted to move along $x$-axis between $x=0$ and $x=a$, where $a$ is of nanometer dimension, its energy can take only certain specific values. The allowed energies of the particle moving in such a restricted region, correspond to the formation of sta …

When a particle is restricted to move along $x$-axis between $x=0$ and $x=a$, where $a$ is of nanometer dimension, its energy can take only certain specific values. The allowed energies of the particle moving in such a restricted region, correspond to the formation of sta …

Which one of the following statements is WRONG in the context of X-rays generated from a X-ray tube?

In a mixture of $\mathrm{H}-{\mathrm{He}}^{+}$gas ( ${\mathrm{He}}^{+}$is singly ionized He atom), H atoms and ${\mathrm{He}}^{+}$ions are excited to their respective first excited states. Subsequently, H atoms transfer their total excitation energy to ${\mathrm{He}}^{+}$ions (by …

In a mixture of $\mathrm{H}-{\mathrm{He}}^{+}$gas ( ${\mathrm{He}}^{+}$is singly ionized He atom), H atoms and ${\mathrm{He}}^{+}$ions are excited to their respective first excited states. Subsequently, H atoms transfer their total excitation energy to ${\mathrm{He}}^{+}$ions (by …

In a mixture of $\mathrm{H}-{\mathrm{He}}^{+}$gas ( ${\mathrm{He}}^{+}$is singly ionized He atom), H atoms and ${\mathrm{He}}^{+}$ions are excited to their respective first excited states. Subsequently, H atoms transfer their total excitation energy to ${\mathrm{He}}^{+}$ions (by …

A radioactive sample S1 having an activity of $5\mu \mathrm{Ci}$ has twice the number of nuclei as another sample S2 which has an activity of $10\mu \mathrm{Ci}$. The half lives of S1 and S2 can be

In the options given below, let $E$ denote the rest mass energy of a nucleus and $n$ a neutron. The correct option is

The largest wavelength in the ultraviolet region of the hydrogen spectrum is 122 nm. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is

STATEMENT-1
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-rays do not change.
because
STATEMENT-2
When an electron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.

Some laws / processes are given in Column I. Match these with the physical phenomena given in Column II and indicate your answer by darkening appropriate bubbles in the 4 × 4 matrix given in the ORS.
| (A) Transition between two atomic ener …

Electrons with de-Broglie wavelength $\lambda$ fall on the target in an X-ray tube. The cut-off wavelength of the emitted X-rays is

The graph between $1/\lambda$ and stopping potential (V) of three metals having work functions ${\varphi }_1,{\varphi }_2$ and ${\varphi }_3$ in an experiment of photo-electric effect is plotted as shown in the figure. Which of the following statement(s) is/are correct? [Here …

Match the following Columns
| (C) $\beta$-decay | (R) Generally possible for nuclei with high …