# MHT-CET Physics Crash Course Energy of Bohr’s Orbit Class 12

## “Energy of Bohr’s Orbit” MHT-CET Class 12 Physics Crash Course| Chapter Structure of atoms and Nuclei

In this session G.S. Khairnar will discuss the theory and MCQ’s of Energy of Bohr’s Orbit. The session will be useful for all the aspirants of MHT-CET 2022. The session will be in Marathi and English.

### Energy of Bohr’s Orbit:- ### Let’s discuss the concept of energy of Bohr’s orbit…….!

Consider electron of mass m & charge ‘e’ revolve round the nucleus in circular orbit of radius ‘r’

Let V be the speed of electron then,

As electron of mass m, charge e revolves round the nucleus in circular orbit of radius r.  It possesses Kinetic energy as well potential energy.  Then the total energy ‘E’ is given by,

E = K.E.   + P.E.  ……………………………(1)  ■ This is the energy of electron in lowest orbit called as ground state energy.

Binding energy: The minimum energy required to make electron free from the nucleus, is called Binding energy of electron. This energy is also called ionization energy of hydrogen atom. ### Energy of Bohr’s Orbit MCQ’s:-

Let’s try to solve the following MCQ’s based on Energy of Bohr’s Orbit….!

Q.1) The minimum energy required to make electron free from the nucleus, is called as….

1. a) Kinetic energy of electron
2. b) potential energy of electron
3. c) ionisation energy of electron
4. d) electric energy of electron

1. c) ionisation energy of electron.

Q.2) Kinetic energy of electron in Bohr’s hydrogen atom is given as………. Q.3) Electric potential due to electron is given as, Q.4) Total energy electron in nth Bohr’s orbit is………

a) directly proportional to square of principal quantum number

b) directly proportional to principal quantum number

c) inversly proportional to square of principal quantum number

d) inversly proportional to principal quantum number

Answer: c) inversly proportional to square of principal quantum number

Q.5) Binding energy of electron in 1st orbit of hydrogen atom is……. Q.6) Amount of energy required to remove an electron from the 2nd orbit of carbon atom is…….

a) +122.4 eV
b) -122.4 eV
c) -12.24 eV
d)+12.24 eV Q.7) The ratio of ionization energy of electron in 3rd orbit to 2nd orbit of copper atom is …

a) 9:4
b) 3:2
c) 2:4
d) 4:9 Q.8) Energy of electron in first orbit of sodium atom is -1645 eV, Energy of electron in 3rd orbit of sodium is …

a) +1,645 eV
b) -1,645 eV
c)-182.8 eV
d)+182.8 eV Q.9) Ratio of kinetic energy to potential energy of electron in 1st Bohr’s orbit is… ### ♦जिल्हा नुसार जाहिराती ♦

अहमदनगर अकोला अमरावती औरंगाबाद भंडारा बुलढाणा
चंद्रपुर धुले गढ़चिरौली गोंदिया हिंगोली जलगांव
जालना कोल्हापुर लातूर मुंबई नागपुर नांदेड़
नंदुरबार नाशिक उस्मानाबाद पालघर परभानी पुणे
रायगढ़ रत्नागिरि सांगली सातारा सिंधुदुर्ग सोलापुर
ठाणे वर्धा वाशिम यवतमाल बीड

### ♦शिक्षणानुसार जाहिराती ♦

७ वी (7th) दहावी (SSC) बारावी (HSC) डिप्लोमा आय.टी.आय पदवी
पदव्युत्तर शिक्षण बी.एड एम.एड एल.एल.बी / एल.एल.एम बीएससी एमबीए
बीसीए एमसीए बी.कॉम एम.कॉम GNM/ANM एमएससी
बी.फार्म एम.फार्म बी.ई एम.ई BAMS/BHMS एम.बी.बी.एस / एम.डी
बी.टेक एम.टेक MS-CIT