MEDIUM

JEE Advanced

IMPORTANT

Earn 100

In a hypothetical Bohr hydrogen, the mass of the electron is doubled. The energy $E_{0}$ and radius $r_{0}$ of the first orbit will be ( $a_{0}$ is the Bohr's first orbit radius of hydrogen)

50% studentsanswered this correctly

Important Questions on Modern Physics

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 26

Imagine an atom made up of a proton and a hypothetical particle of double the mass of the electron but having the same charge as the electron. Apply the Bohr atomic model and consider all possible transitions of this hypothetical particle to the first excited level. The longest wavelength of a photon in the Balmer series has a wavelength

λ

(given in terms of the Rydberg constant

R

for hydrogen atom) equal to

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 27

A photon has the same wavelength as the de-Broglie wavelength of electrons. Given that, $c =$ speed of light and $v =$ speed of the electron. Which of the following relation is correct? [where, $E_{e} =$ the kinetic energy of an electron, $E_{ph} =$ the energy of the photon, $p_{e} =$ the momentum of electron and $p_{ph} =$ momentum of photon]

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 28

The ratio of the speed of the electron in the first Bohr orbit of hydrogen and the speed of light is equal to (where

e

h

and

c

have their usual meanings)

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 29

In a hydrogen atom, the binding energy of the electron in the ground state is

E_{1}

. Then, the frequency of revolution of the electron in the

n^{th}

orbit is

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 30

The de-Broglie wavelength of an electron in the

n^{th}

Bohr's orbit of the hydrogen atom is

λ_{n}

and the angular momentum is

J_{n}

, then

HARD

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 31

When photons of energy

4.25 eV

strike the surface of a metal

A

, the ejected photoelectron have maximum kinetic energy

T_{A}

expressed in

eV

and de-Broglie wavelength

λ_{A}

. The maximum kinetic energy of photoelectron liberated from another metal

B

by photons of energy

4.70 eV

T_{B} = (T_{A} - 1.50) eV

. If the de-Broglie wavelength of these photoelectrons is

λ_{B} = 2 λ_{A}

, then

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 32

The electron in a hydrogen atom makes a transition

n_{1} \to n_{2}

, where

n_{1}

and

n_{2}

are the principal quantum numbers of two states. Assume the Bohr model to be valid. The time period of the electron in the initial state is eight times in the final state. The possible values of

n_{1}

and

n_{2}

are

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Physics Vol 2>Chapter 9 - Modern Physics>Objective Problems [Level 2]>Q 33

A photon of energy

E

ejects a photoelectron from a metal surface whose work function is

W_{0}

. If an electron having maximum kinetic energy enters into a uniform magnetic field of induction

B

in a direction perpendicular to the field and describes a circular path of the radius

r

, then the radius

r

is given by, (in the usual notation)

In a hypothetical Bohr hydrogen, the mass of the electron is doubled. The energy E0 and radius r0 of the first orbit will be (a0 is the Bohr's first orbit radius of hydrogen)

Important Questions on Modern Physics

Learn and Prepare for any exam you want !

In a hypothetical Bohr hydrogen, the mass of the electron is doubled. The energy $E_{0}$ and radius $r_{0}$ of the first orbit will be ( $a_{0}$ is the Bohr's first orbit radius of hydrogen)