Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Communication

Question:

The study of hydrogen atom spectrum has mainly five series. Choose the correct sequence of these series in increasing order of their shortest wavelength.

A. Lyman Series

B. Pfund Series

C. Paschen Series

D. Bracket Series

E. Balmer Series

Choose the correct answer from the options given below:

Options:

B, A, D, C, E

B, C, D, E, A

A, E, C, D, B

A, C, E, B, D

Correct Answer:

A, E, C, D, B

Explanation:

Spectral series in hydrogen atoms corresponds to

A. Lyman Series{ n1 = 1 , n2 = 2,3,4.....} – Ultraviolet

E. Balmer Series { n1 = 2 , n2 = 3,4,5 .....} – Visible

C. Paschen Series – { n1 = 3 , n2 = 4,5,6.....}Infra-red

D. Bracket Series – { n1 = 4 , n2 = 5,6,7.....} Infra-red

B. Pfund Series – { n1 = 5 , n2 = 6,7,8.....}Far infra-red

With increase in number of n1 the gap between two consecutive level decreases and hence wavelength increases. Correct sequence of increasing order of their wavelength is A, E, C, D, B.