## MCQ (Single Correct Answer)

The ionisation potential of hydrogen atom is $$-$$13.6 eV. An electron in the ground state of a hydrogen atom absorbs a photon of energy 12.75 eV. How...

Which of the following statements is correct?

If the kinetic energies of an electron, an alpha particle and a proton having same de-Broglie wavelength are $${\varepsilon _1},{\varepsilon _2}$$ and...

Suppose in a hypothetical world the angular momentum is quantized to be even integral multiples of $${h \over {2\pi }}$$. The largest possible wavelen...

A 12.5 eV electron beam is used to bombard gaseous hydrogen at ground state. The energy level upto which the hydrogen atoms would be excited is

Let r, v, E be the radius of orbit, speed of electron and total energy of electron respectively in H-atom. Which of the following quantities according...

If R is the Rydberg constant in cm-1, then hydrogen atom does not emit any radiation of wavelength in the range of

A proton and an electron initially at rest are accelerated by the same potential difference. Assuming that a proton is 2000 times heavier than an elec...

To which of the following the angular velocity of the electron in the n-th Bohr orbit is proportional?

How the linear velocity v of an electron in the Bohr orbit is related to its quantum number n?

If the half-life of a radioactive nucleus is 3 days, nearly what fraction of the initial number of nuclei will decay on the third day? (Given, $$\root...

An electron accelerated through a potential of 10000 V from rest has a de-Broglie wave length $$\lambda$$. What should be the accelerating potential, ...

The de-Broglie wavelength of an electron is $$0.4 \times {10^{ - 10}}$$ m when its kinetic energy is 1.0 keV. Its wavelength will be $$1.0 \times {10^...

Radon-222 has a half-life of 3.8 days. If one starts with 0.064 kg of radon-222 left after 19 days will be

## MCQ (More than One Correct Answer)

A sample of hydrogen atom in its ground state is radiated with photons of 10.2 eV energies. The radiation from the sample is absorbed by excited ioniz...

Let vn and En be the respective speed and energy of an electron in the nth orbit of radius rn, in a hydrogen atom, as predicted by Bohr's model. Then...