GOV EXAM ADDA

1. The value of Bohr radius of hydrogen atom is

A. 0.529 ×10-9 cm

B. 0.529 ×10-10 cm

C. 0.529 ×10-7 cm

D. 0.529 ×10-8 cm

Answer & Solution

2. Bohr’s concept of the orbit in an atom was contradicted by

A. Plancks hypothesis

B. Hunds rule

C. De Broglie relationship

D. Uncertainty principle

Answer & Solution

3. Which of the following atoms has a nonspherical outermost orbital

Answer & Solution

4. In an atom the order of filling up of the orbitals is governed by

A. Pauli’s exclusion principle

B. Uncertainty principle of Heisenberg

C. Hund’s rule

D. Avogadro’s law

Answer & Solution

5. If r is radius of first orbit, the radius of nth orbit of the hydrogen atom will be

Answer & Solution

6. In Lyman series an electron jumps from higher energy level to

A. L energy level

B. N energy level

C. K energy level

D. M energy level

Answer & Solution

7. Orientation of atomic orbital is controlled by

A. Electron spin Quantum number

B. Azimuthal Quantum number

C. Principal Quantum number

D. Magnetic Quantum number

Answer & Solution

8. According to Aufbau principle, the correct order of energy of 3d, 4s and 4p orbitals is

Answer & Solution

9. When a metal is hearted in a flame, the electrons absorb energy and jump to higher energy state. On coming back to the lower energy state, they emit light which we can observe in

A. Fluoroscence

B. Absorption spectra

C. Raman spectra

D. Emission spectra

Answer & Solution

10. In which region of electromagnetic spectrum does the Lyman series of hydrogen atom lie?

Answer & Solution

11. Two electrons in an orbital are differentiated by which of the following?

A. Principal Quantum number

B. Azimuthal Quantum Number

C. Magnetic Quantum Number

D. Spin Quantum number

Answer & Solution

12. When an electron drops from a higher energy level to a low energy then

A. Atomic number increases

B. Atomic number decreases

C. Energy is absorbed

D. Energy is emitted

Answer & Solution

13. The total number of orbitals in a principal shell are

Answer & Solution

14. All the four quantum numbers of two electrons in an atom are not same. It is the law of ____

A. Avogadro’s law

B. Uncertainty principle of Heisenberg

C. Hund’s rule

D. Pauli’s exclusion principle

Answer & Solution

15. The total energy of revolving electron in an atom

A. Can never be positive

B. Will always be positive

C. Cannot be negative

D. Can have any value above zero

Answer & Solution

16. The mercury and sodium street Lamps light up because of

A. Atomic emission

B. Electron emission

C. Atomic absorption

D. Electron absorption

Answer & Solution

17. When there are two electrons in the same orbital, they have

Answer & Solution

18. The spectrum of helium is expected to be similar to that of

Answer & Solution

19. The atomic orbital is

A. Three dimensional field around nucleus

B. The region in which there is maximum probability of finding electron

C. The Circular of the electron

D. Elliptical shaped orbit

Answer & Solution

20. Which orbital is dumb bell shaped

Answer & Solution