TG EAMCET 2 May 2025 Shift 1 Paper

The frequency for hydrogen spectral lines is found using:
f=RC(‌

1

n12

−‌

1

n22

)
Lyman Series (moving to n1=1 ):
First line: Electron goes from n2=2 to n1=1
f1(L)=RC(1−‌

1

4

)=RC‌

3

4

Second line: Electron goes from n2=3 to n1=1
f2(L)=RC(1−‌

1

9

)=RC‌

8

9

Difference between the two Lyman frequencies:
f‌=f2(L)−f1(L)
‌=RC(‌

8

9

−‌

3

4

)
‌=RC(‌

32−27

36

)=RC‌

5

36

Balmer Series (moving to n1=2 ):
First line: Electron goes from n2=3 to n1=2
f1(B)=RC(‌

1

4

−‌

1

9

)=RC‌

5

36

Second line: Electron goes from n2=4 to n1=2
f2(B)=RC(‌

1

4

−‌

1

16

)=RC‌

3

16

Difference between the two Balmer frequencies:
f′‌=f2(B)−f1(B)
‌=RC(‌

3

16

−‌

5

36

)
‌=RC(‌

27−20

144

)
‌=RC(‌

7

144

)
Relationship between differences:
‌‌

f′

f

=‌

( 7 144 )

(‌ 5 36 )

=‌

7

144

×‌

36

5

=‌

252

720

=‌

7

20

‌f′=‌

7

20

f